Glass4strength or thicker foam

[moya]

Hey guys

im buying a JS board in a couple of days. Im going the Luke egan model but trimming it a touch to 6'4" x 19 x 2&3/8
My current board is 6'2"x18&2/8x 2&2/8. I want something a bit heavier and more solid to carve with, hence the JS luke model.
Would anyone advise going 2.5' thick for a significant difference to my current board or do you think the width and length will blow it out enough?

I want this JS to last a few years and was Wondering about glassing.

I have heard of people going 4x4 on the deck and 6 on the bottom instead of the usual vice versa. Has anyone had experience with this and how the deck holds up to depressing?

Also how much extra weight will going 6 on top and 6 on the bottom add?
Will it be quite a dramatic difference to my current board?
Would going 2.5" thick add any weight and strength or is it best to think in terms of thickness for bouyancy and glassing for strength and weight?