6'10"?! That should be adequate for just about anyone, less than 350 pounds. You don't play NBA basketball in Miami do you?
Dennis and I made him a 6'2" that was about...shoot, just a shade over 2 inches thick and it was more length than he needed. Dennis at the time was around 250 lbs. The biggest problem with that length board is that the nose would grab in the flats on hard turns. We are in the process of making him one that is about 5'2" and 2+ inches thick.
By sticky foam are you referring to the EVA foam found on most commercially available wakesurfers? Larry Mann at Trick Boardz sells some: www.trickboardz.com
Poor Boys sells traction pads and square sheets, I believe 9 x 12 (The site is miserable to navigate, get to the surf section and then check for traction pads) www.poorboyusa.com
I also know that there is a "gator grip" or something LIKE that name which is EVA foam with the 3M adhesive backing. It's used for trailer fender grip.
I know that there is a large craft store supplier. McMaster-Carr Supply Co. They have a ton of EVA foam in various thickness with 3M adhesive backing. I can't seem to copy a link to the specific page, but do a search for EVA Foam on their site and you should be able to locate what you want online. www.mcmaster.com
Hope that helps.