the ARC you posted looks the easiest – are you on crack.
its the cheapest yes …. thats about all.
ive got both and i suggest you get a mig first up
the one you linked will weld your 3/4mm stuff no bother but youll spend quite a bit of time learning the movement and it wont be nice looking
if you want easy to learn for a novice and easy to get a nice finish thats strong
http://www.machinemart.co.uk/shop/product/details/151te-turbo-mig-welder
Its like a hot metal glue gun – get your feed rate and power right and its simple as making lots of letter es down the join.
have you got a good grinder – prep work is key for any welding.
my arc only comes out for locations where i cant get the mig torch in at a suitable angle – you can feed arc electrodes into small spaces such as when i patched my bulkhead outrigger without taking the bulkhead floor pan out 😀 – little hate box.
there are better places than machine mart to get welding equipment also, i bought there as i knew no better . try weldquip.
also if you do get one from machine mart throw that hand held mask to hell and get an auto darkening flip down mask – makes a world of difference.