Looking for the right board for me. Help

First off i do not really have a way to demo so that is why I am seeking help here.

I am 6'4" and hover around 230lbs. I am starting to work on grabs and trying to get more pop.

I have bought and tried the following.

06 Sol
04 Tripp 143
05 Valhalla 143
08 Murray 145

I sold the Sol so i do not have it any more. I did get to ride the Murray 140 when it was being mailed around and I really loved it. I got a 145 (w/ CT)due to my size and just me thinking it would be better and it doesnt seem to pop me much at all.

The Tripp out of all of these has progressed me more then anything and that is what I am currently riding, with Zeus bindings.

Do i need to be on the biggest board out there? Is it possible that I am doing better on tripp because it is smaller?

Would a flex board help a bigger guy get more pop? I edge good from what my friend says and I am standing tall. I am just trying to find a board that can help me get more pop. I am also working on the basics edging, standing tall, and handle positions to help also.

Thanks if you can help me lol! Sorry if i lost you in my train of thought above also!