Its ok! Learning alot through the hard way, though. My costume is starting to near completion, but I'm having a much harder time on the shins than I would have expected. (Seriously, the thighs themselves were 12 pages of pure madness.)
Things of note:
Low temp hot glue seems to work ok, havent noticed any issues with it. I think the only problem with it is the gun itself, all low temp guns I've seen are fine for quick uses. If you're building this suit, invest in a 20 dollar comfortable hot temp gun, It'll save your hands from agony.
For mats, I have found KMart and no other place to have them consistantly in stock. They are always by the automotive section. Also the cheapest at 7 bucks for a 6 sheet pack.
For sealing, I can't ever seem to get my glue the right consistancy, so I've been using just pure glue on it.
Latex primer, if you can find it, its a god send.
Hope some of the tips help.