Log Surfboard Glassing

Currently building 10'er. Shaped blank from polysterene installed ply stringer. Attempting to replicate tradition 50/50 rail single fin less a little weight (I know the weight is kin to the Log).

Epoxy Kinetix R104 and glass is it better to layer glass. Is 2x 4oz layers stronger than 1x 10oz layer? If I used carbon fibre is it best bottom or top at $50.00 a metre I hoped to only have the black weave on one face.

Really enjoy the knowledge bank available on line, thanks. 

'60s logs were double 10 oz, standard. The foam was a higher density and weight per cu ft. So the blanks were heavier than modern poly to begin with. If you are using a lightweight blank and don’t mind a board with some heft I’d go double six, top and bottom.