If you’re going to learn, ski downhill and then get into Scottish backcountry, it’s not too hard to get a good all round setup that will do everything well.
A lot of Scottish skiers now do all of their riding on touring kit. Several manufacturers produce Alpine touring bindings, similar in function to the classic Fritschi from Diamir, allowing for uphill travel on skins. This sort of binding behaves very much like a downhill (or ‘Alpine’) binding when actually skiing.
Dynafit gear (bindings and boots with a specific interface, not compatible with ‘standard’ kit) is very light and very expensive indeed. Not recommended for beginners.
Many skis can be drilled to take touring bindings instead of classic Alpine sets. Ski choice for you is a matter of looking for good deals, avoiding brand snobbery and making sure that you don’t get something either too basic nor too stiff, as you’ll struggle to learn.
Some would suggest that buying a cheapo set of standard skis/bindings to begin to learn on might be wise, then sell them on to reduce losses.
Personally, I’d say buy a good boot early on, rent skis for a couple of trips then buy your touring setup.
Eventually, you will want a touring ski around 175-180cm long and about 90mm underfoot at the narrowest point, maybe 120-130mm up front.
Boots- take a look at the hybrid touring boots from the like of Salomon, called Quest. Again, others make similar style boots that do both tasks well but the most important thing is to make sure that you get fitted by a good shop, so that you buy the brand of boot that fits you best. There is a lot of variation in the shape of last in ski boots.
Remember that when you are ready to start touring, you need to budget for skins at £120 ish and if you don’t already have it, backcountry safety gear in a decent backpack.
There are a lot more folk touring on skis in the Highlands than take their bikes up into the hills here in the summer. Shops like Braemar Mountain Sports will help you loads and will sometimes do deals if you buy a few things together. Craigdon have shops in Perth & Aberdeen, Blues are also in Perth, Edinburgh, Glasgow. On-line, Facewest in the UK and Telemark Pyrenees in France are both worth looking up.