Thinking about a ATI 4870 - compatibility issues?

[G33K]

I'm in the market for a new graphics card. I've been considering an HIS ATI Radeon HD 4870, but I'm not sure if it's compatible.

My rig as it stands:

DF LanParty Ultra-D
AMD Opteron 148
2 x 7800GT's (which I run in SLI for games and three monitors at other times)
2 x 1GB Corsair XMS RAM

Ideally I'd just like to replace one card with something that'll allow me to run L4D in 1920x1200 (the native res of my center monitor). From what I gather though, I can't run NVidia and ATI cards at the same time? So I'd have to buy two new cards to be able to run all three monitors?

My other concern is whether or not there are going to be any problems running ATI cards on that motherboard? I understand that crossfire wouldn't work, but if the primary card is powerful enough, to run games I wouldn't need it.

If anyone can confirm / clarify any of that for me I'd be very grateful

 

[Ben M]

I think that you've got it spot on.

You can't crossfire on that board.
you can use a secondary card for your second and third monitors, it doesn't need to be powerful, so just get something cheap and passive.
You can't (/ it's very difficult to) use one ati and one nvidia card

 

[G33K]

I'm happy to buy another card if that means I can still run all three monitors. Maybe something like an XFX ATI Radeon HD 4650?

Do the ATI drivers allow you to rotate screens? I like to have my two widescreen side-monitors in portrait