I don't really understand why you want 2 cards? If you can wait maybe something like the 6770 maybe able to fill both roles if you think a single 5770 is not fast enough.
I'm running 4 monitors
Please remember that any mention of competitors, hinting at competitors or offering to provide details of competitors will result in an account suspension. The full rules can be found under the 'Terms and Rules' link in the bottom right corner of your screen. Just don't mention competitors in any way, shape or form and you'll be OK.
I don't really understand why you want 2 cards? If you can wait maybe something like the 6770 maybe able to fill both roles if you think a single 5770 is not fast enough.
How about a 5770 flex then, can do 4 monitors 1 needs to be DP though.
http://www.overclockers.co.uk/showproduct.php?prodid=GX-248-SP&utm_source=froogle
Just got a 460 it was I thought the only one capable until the 450. Had some HDMI issues detecting my Onkyo all good now, way more efort than the 5770 for sure. Spent about 2 hours trying to get the colours etc correct. It says it can now bitstream everything. Will be giving it a good test tommorrow. I'll let you know.
I didnt think you did, clears that up anyway. The 5770 flex may well be able to run 3 monitors and feed your projector over hdmi as well.