Wow, you've certainly been busy! Looks great! I like the alternating colors on the football.
I know some people who have done projects with that tinted resin and they look great. From what I've seen, the stuff must be plenty durable and strong enough to use on your decks. I'm not sure though, I haven't seen anything done with it in a thin (1" or less) situation like the decks would be. That would look really cool...
6 oz is standard. If you wanted to go with 4oz I imagine most people would recommend doing a football shaped piece on the bottom and then a full-length piece on the outside. For your goals with the canoe I would suggest doing one solid piece, I've played around a bit and have a hard time getting the edges to look nice, even though you'd be covering the edges of the football piece with another layer it would still be there... You could also do 6oz on the outside and 4 on the inside for a little weight-savings.
S glass is more expensive and more durable from what I understand. It doesn't scratch as easily as E-glass, but it still scratches. E-glass is the standard, and I believe easiest to work with and possibly also the clearer or the two? I've read many posts here that talk about the differences and of course can't find them right now... Hopefully someone else chimes in after this bump.
Zac