Layer 2 or layer 3 Switch

Anyday with your requirements I would suggest going for Layer 3 device so that you could eliminate the extra hop. With VoIP, you obviously want to do the vlans right? so do the routing in there as well - will be much faster and easy management.

Cheers,
Rajesh

I think it really comes down to whether or not you are using vlans and mixing with your other traffic.  VOIP is going to have to go out the router anyway.  You can save your internal traffic from hitting the router by implimenting a layer 3 switch which in turn will free up your router to process those VOIP pakcets quicker.  Layer 3 is king here, much more flexability, especially  if your not sure how you want to do it up front.  

In what situation would you have layer 2 switch? does the extra Hop make that much of a difference (nano secs) as layer 2 is faster

It is not just about the speed in information transfer. It is about the number of hops and connections that you need to maintain and troubleshoot.

Cheers,
Rajesh

layer 3 always a better overall solution ????for troubleshooting etc