Just because it's big, why must it be heavy

Your issue is early wave entry and to me, that means you need volume not weight, so every square inch of volume you have should be dedicated to floating you, not the board itself.
I recently borrowed a very heavily glassed board for a test, it was the Issac Fields model from Bennett's, it was so hard to pick up waves, I was reduced to catching whitewater and trying to ride out into the clean water, it was hopeless.
As I was getting out of the water to grab old faithful and go back in for a real surf, a buddy of mine was going in and he said something that will stick with me for a long time. He said he borrowed the same board and he also thought it was useless and he reckons that the reason it's called an Isaac Fields model is because he's the only one who can ride it.
That's when I realized that board weight may be a good thing for someone like Isaac who would be lucky to be 11 stone ring'n wet, but for a big bloke, it's just another burden to overcome.