: Would like to keep it light, : strong, and affordable.

Reminds me of the old joke. Punch line: Pick any two.

Seriously, though...
You've gotten some excellent advice - especially the point about carbon fiber cloth weight - 5.7oz CF cloth is at least twice as thick as 6oz glass, and needs a lot more epoxy (and weight). If you are using a (stiff) wood core, I don't see much sense in using a lot of CF cloth, though it is great in the right places (coamings, hatch recesses, fittings).
Re: lightweight glass cloth- be careful, as some of the 3-4oz cloths are very stiff and difficult to wet out (I bought quite a lot of that by mistake..). Probably a supplier like RAKA is a good bet for getting the right advice (??).

I've had good service from The Composite Store (decent prices and they ship to Canada without a lot of extra fees).
http://www.cstsales.com/
CST does list the 'drape' and 'thread count' for all their cloth - pay attention to more than the 'price' column and avoid my mistake.

I've also gotten very good service from Soller Composites, though mostly for glass and carbon sleeve material (not cut cloth).
http://www.solarcomposites.com/