If you can afford it and your PSU can handle it, get a 5850 or 5870. They're at excellent prices right now. Otherwise, the 5770 will get it done for you. The forgotten 5830 is worth $15 more than a 5770 if you find it for that price.
A 5670 is a marginal gaming card--just barely entry level and will not play Black Ops well. 2 monitors won't affect your gaming since one will typically shut off when you game. The GT 440 doesn't really count as a gaming card--more a multimedia card that can play games if you happen to install some. If you're that strapped for cash, wait for an excellent deal like the $50 (no rebate, no coupon) 9800GT Tiger Direct had yesterday.