What type of wood and where to get

that is going to get wet and warped. it just is. you need gaps to let water fall through atleast.

something tropical if you must but I reckon you'll regret it. Accoya might be an alternative option. either way prepare yourself before you look at the price

I mean I also think its a horrible table but thats personal taste.

Keruing is a resinous wood if you don't plan on regularly re-finishing the table. It can be a bit coarse-grained and vary in colour so have a look first
Teak can be a bit dodgey because of either illegal logging or supporting the military coup in Burma/Myanmar. It can be obtained quite legally with a good provenance though. Older reclaimed teak might be a better option
Lignia is a manufactured resin-impregnated softwood that I know nothing about but might be worth a look, it's used in boat decking

You’ve got a handful of problems in translating that design to something that will work here in the uk, some hinted at above.

The design calls for pine. It’s all dimensioned in inches. Timber here will be in mm and not an exact 2”x4” match.
Second, “pine” in Texas will likely be southern yellow pine, a rather hard species of pine which is cheap and readily available there, whilst being a stout grade of softwood.
Third, and this is the kicker, that table design might work in a Texas garden, especially when built out of southern yellow pine, but it will warp and rot in the UK, especially when built from Douglas fir or similar.

Here in our climate, there’s a reason good quality outdoor furniture is built from quality hardwoods such as oak. Occasionally overlooked are outdoor suitable softwoods such as larch. I wouldn’t be considering tropical hardwoods myself for several reasons.

Another factor is you’ll probably be shocked when you tot up the cost of even cheap softwood to the linked design that will bow and twist within a season here in the uk. Go to the wickes website and price it up for PSE whitewood.

In short, back up, think again. Unfortunately the design you’ve linked won’t really translate. Need to look at timber that is available locally (and yes that was your question) but also a design that’s sympathetic to the timber available and the climate here.

I wouldn’t be considering tropical hardwoods myself for several reasons.

no neither would I just suggesting limited options

Reclaimed tropical hardwoods are available but very expensive.
Greenheart, azobe (ekki) or jarrah - in that order - would be my shortlist.
All are:
- harder, more dense and heavier than oak
- unworkable without pro quality, heavy duty woodworking tools
- difficult to find as untreated timber
Teak would be a possibility.
I don't think your plan is worth the effort.
Avoid pine - or any other softwood - as it will look like shit within 12 months, irrespective of any treatments you use.

Teak or oak should be what you're looking for. I've got a garden bench that needs all the slats replacing and I'm keeping my eyes out for cheap garden furniture in Aldi or B&Q etc, or charity shops that I can cut up and repurpose.

I'd look to use something far less exotic and treat it ever year.
Decking or scaffold boards seem to cope with arduous environments and constant use, I'd start there.

Can be had for relative peanuts on Facebook Marketplace and when finished and stained properly, look as good as they need to - unless you really crave the 'look at me' wow factor table. (Understandable if so, as I'd love such a table - just wouldn't use it outside)

Look on eBay for old laboratory benches

Lots of good advice already but it's not the right design for the UK environment unless you plan on making it a cover, it'll live under a roofed patio area or somesuch.

The current state of timber prices is depressing. It impacts me at work plus also for the home projects I would like to be tackling. I'm lucky as I have access to table saws, planer thicknesser and enough power tools that I can tackle taking on unprocessed stock which opens up options. But even then the cost is stopping me currently. Even when you do happen upon a more realistic design, be prepared to be surprised at the cost. If your significant other values such things by the cost of an 'anequate' B&Q equivalent have your reasoning ready as to why you want to spend multiple time more just on the materials and spend all that time too. This project will cost you money to give you a hopefully nice experience. If you'll get the warm afterglow of being proud of the thing you sit at for years to come and improved long term value as it outlives the shop bought equivalent is down to your skill and ability to make a good decisions about design and material choice now.

Iroko is what we made lab benches from it will kill you faster than the chemicals that where mixed on it. Also used it on Blackpool Pier.
Rock hard and should be left in the rain forest.
Make a table from green oak and let it twist and age like we all do.

Iroko is what we made lab benches from it will kill you faster than the chemicals that where mixed on it

Are you sure that you mean Iroko? Hazard-wise it's similar to Teak. Greenheart mentioned above is worse, even the splinters turn septic ):

Id suggest Western red cedar. Ebay as where to get it.

Red Cedar is the ideal outdoor timber. Often used for outer cladding, shingles and even outdoor furniture-tables/chairs etc.

.

Example -

https://www.ebay.co.uk/itm/185416367690?hash=item2b2bad3e4a:g:XyYAAOSwxJtidl~Q

So here is 12 pieces at 1.2m long. so if you think to make the herringbone shape, the pieces would be 11-12", thats 3 per board, or 36 total, which looking at the pic you have is more than needed. So the rest could be rails, legs. Legs can be made by gluing strips together to make them thicker/wider.

@timba
Yup horrid stuff half the workshop would have splinters that went puss ridden. The other half would get nose bleeds/ breathing issues.
I banned it in the workshop at the end.

Added to the fact that making sure people use PPE can be a pain
I had one painter who would burn through his masks with a fag so he could "keep me fu**ing mask on" and smoke at the same time even though I banned smoking in the paint/Finnish shop .
Ah fun times