should I build an e revo or an e maxx????

Here is my dilema.
A group of friends I race mini z f1's with want me to get involved in their nitro revo racing. Most of the members have evo 3.3 and some have 2.5's. I would like to get involved, and have read alot of the threads in this forum to find out more about brushless power. My question is. I want to run with thier nitro. Do I build an e revo, or do I build a new e-maxx? I noticed that the nitros run around 40 so I definately want to keep up. But what is the best chassis revo or new emaxx that I can build for that speed and runtime? Thanks in advance for helping out a newbe.