Time to upgrade to new board?

I'm thinking it's time for me to upgrade to a new board... I'm currently riding a 2003 CWB Nirvana (http://www.wakeworld.com/BoardGuide/getboard4.asp?ProductID=1714) which is a great beginner board, but now that I'm progressing (trying to get more air and cutting harder, etc.), it's just not working that great for me anymore. The one thing I've noticed this season is that when I try to cut hard hs towards the wake for a jump, it will frequently slide out from under me (it only has the two big center fins).

I'm in need of some suggestions on boards that I could look at as a replacement for the Nirvana. I'm 5'5" and about 135 lbs. Not sure if it makes a difference, but our boat doesn't put out a huge wake (not bad though) and usually I'm riding in somewhat choppy water. Right now I'm pretty confused on what features would be the best for my skill level, etc. (i.e. length, weight, rocker type, fins, tip type, etc.).

Any suggestions are welcome! Thanks!