Hello Bill..
Yes... you need to lam 2 layers of 3/4" ply for your stringers. .. then Glass them in ( Pics of your prepwork/grindout would be great ).
The 1 qt bucket of "Cabosil filler" made for epoxy only..never heard of that. Its just a powder that you mix with whatever resin system you want to use.
Your Lam resin is hard to tell from just your pics .. even on my 19". It looks like its Laminating resin which is what you want ( Low VOC resins I have found has longer cure times and is obviously less Gassy ).
Your getting more then 5 qts of resin right ?
..
Your cabosil will normally take a 1:1 ratio ( 1 qt of cab to 1 qt of resin ).
I never use the 1/4" chopped glass in a bucket ( even though I have it on hand ) .. I just scissor up some CSM into the mix.
Ask away anytime
YD.