What weight cloth ?
 

What weight cloth should I use for my new transom? How many layers should I do on each side ? I was thinking about 6 oz. or even 10 oz?

Me, I generally use the heaviest/thickest cloth that the mold/repair will allow.
Here are some links to sites Skools has posted before.
http://www.wellcraftv20.com/communit...ght=fiberglass
http://www.wellcraftv20.com/communit...ght=fiberglass

And scroll through the "links" section, there are other posters with other stuff you might need.

you don't want to heavy due to it soaks up alot of resin and will crack plus give you too much transom weight from the resin. several lighter layers is stronger that 1 or 2 heavy layers.