Looking for a 10G core switch...

So, until recently I was using VLANs to break apart my networks. I used my Sonicwall router to route traffic between subnets...

Well, I also recently upgraded my network and I have 30G LAG connection between floors, and 20G LAG connections to individual 48 port switches, and 20G LAG connections to each server.

With this much bandwidth, the router is just a bottleneck, and I should stick to using it for Internet access, and inbound rules, not much else.

So, I figured I need a core switch, which is really just a switch with L2 routing support. I've never used one before, so really don't know what I should be looking for. I really need something that supports 10G. SFP+ is preferred.

What other features should I be looking at?

I'm looking at the less expensive end of the spectrum, any models that anyone can recommend?