I have this configuration running and I have 4 monitors.
The Eyefinity software for Radeon will allow you to use multiple monitors for gaming, but I think it's way over rated. The spread of 3 monitors in gaming is just way too much for me. Sure it looks kewl, but you can't possibly take in the entire view when sitting at a desk. Plus when switching to 3 monitors, it really plays havoc on your regular desktop applications.
As far as the configuration I have, is as such:
2 HDMI connections. 1 goes connects through a DVI port. The adapter is to HDMI.
1 Display port connection. (This is the monitor I have for gaming @ 144hz).
1 plain DVI connection.
You can add additional monitors by Daisy chaining the display port connection to other monitors.
Only 2 of the monitor connections can be legacy connections.