Welcome to the board ultraboy! So you're upgrading? Personally I'd urge you to look at the pre-2002 models. Like the Z250 Shabah. I absolutely love mine, and they're a pretty common model, so finding one shouldn't be too tough. Since you've already got a Z212, you know about Mariah's z-line and all the options and things, you won't be disappointed. If you're trying to stick around the 25' size, there's a few options, the Z250 is great, there's also the Z258, the Z255, and the Z245ST, which is the bowrider & cuddy combo. We've got members who own all these models, so search around the forum and ask as many questions as you'd like!
In the meantime, here's a couple boat classified sites to check out.
http://www.boats.com
http://www.iboats.com
http://www.boattrader.com