I actually closed it up, I'm currently with heatsinking, sort of in a .
Anyway, i didn't use any batteries in this one, the design wasn't good enough, and the batteries I own, I bought from Zenloc on his garage sale, for about 60$ so I'm no reference.
As for case making, I recommend vaccum forming, it's not that hard, check out the case section of the forums, and some of the pages of another thread of mine actually depict Beta helping me through vaccum forming :
viewtopic.php?f=36&t=4029&start=20
And for the wiikey, I went to the official site, looked for official distributors in france, and chose "arcalide", in two days I had it, it was pretty good. As for wiring, check out ashen's threads, and look for the one about "easily wiring wiikey to ffc"
By the way reading the megastickies over and over again are the best thing you can do to obtain knowledge about portabilising, there's so much useful info there
Good luck !
EDIT: by the way, wiring up a wiikey is pretty hard, took me 3 long tries