I'm making two longboards, one traditional cruzer model and another more progressive shape but not necessarily a high performance comp board. Question: I've only made one longboard before (lots of shortboards) and I glassed it with 2 x 6oz deck and 1 x 6oz bottom. Seemed kind of heavy and sluggish. I was thinking maybe 6oz + 4oz deck and 6oz bottom for the cruzer & 6oz + 4oz deck and 4oz bottom for the progressive shape. Any suggestions? I'm wondering if too much 4oz on the second board will make it structurally weak but I don't want a big heavy board. Help?