Matamp offer suede and leather as an option for covering their amps and cabs, but it is apparently less durable than Tolex! Yes I was suprised, but Jeff Lewis (Mr matamp) told me that. Apparently it is quite easy to apply aswell.
I've bought quite a bit of stuff from Warmoth in the US and every damn bit of it attracts the duties + VAT +customs clearance fee (usually about £10). It usally works out about 20-23% on top of the value of the item and the courier will demand a card payment before delivery. My son has bought some electronics gear from Hong Kong though and got away without paying anything.
No Idea what a cab will cost, the materials aren't that dear to buy, its just the time it takes. As I'm going to make 2or 3 anyway the time taken won't be 2or 3 times the time to make 1. I've already got some black Tolex and some rather nice gold grille cloth that I got from Sid Chaplin.
http://www.vintage-radio.com/trg/ Cheers
Hywel Harris