Can I Add a PCI Video Card to a PCIe-16 Card to get 3 Displays?

I have an nVidia PCIe-16 video card installed providing two displays.
Flight sims work fine, but first-person-shooters suck with the crosshairs split between CRTs (that's 3" of bezel cutting the crosshairs).

Can I add a plain ole PCI video card for a 3rd display?
Would the two cards work together? Does the brand matter or would I need another nVidia?

Triple-Head-To-Go and newer, multi-head video cards are too expensive, while PCI cards can be had for around $30.

I don't play the latest games (MS Flight Simulator 2004; HALO 1; Counterstrike; COD4), although I may upgrade to Flight Simulator X. I am planning on upgrading to two or three 22" LCDs (Acer X223Wbd) in the near future and have game-worthiness questions about those, too...but that's another thread.

My specs:
HP Pavilion a1630n
Athlon 64 X2 4600+ 2.4 GHz
4 GB RAM
WinXP MCE 2005 SP3
EVGA nVidia e-GeForce 8600GT PCIe-16 (512-P2-N757)
Two x 19" CRT monitors (non-widescreen)
3" Bezel-in-the-middle


Thanks in advance,
Dan