Lots of questions spring to mind here
Are you thinking of running the 7 series in sli with the 8 series because you cant.
Do you want dx10 or not you will need to be running vista for this
Why do you"need"2 cards
If you can explain a bit better what you are up to then we will have more idea of how to advise.
ok, sorry let me explain. i have bought a x1950 pro 256 mb. however I'm wanting to connect up 3 monitors. 2x 22" 1680 by 1050 and one 32" lcd tv. though for this i need two cards, so i can have a triple monitor set up. therefore it makes sense to buy another x1950 pro, and put it in cross fire when im playing games, but when i want a triple monitor don't have cross fire on and just use the triple monitor set up. though i was thinking of selling my x1950 pro making a £20 loss ($40) then buying a 8800 gts, so i can play games at the high resolution games at full setting on my 1680 by 1050. then i would have to buy another cheap card so i can have 3 monitors. however a 8800 gts is going for £180 the cheapest, and a 7300 gs is going for about £30, so it would cost me £130 for this option. or an extra £70 for another x1905 pro for the other option. but which would give me the better performance playing games at the resolution i stated 1680 by 1050?
Its pretty tight as far as gaming goes depending on what games you play but i would say get the other 1950 pro as i would see the 7300 as a weak link myself.
With 2 1950s it wont matter which one runs the 32" tv but i shudder to think how a 7300 would manage it.
depending on your current mobo, i would say the 2nd 1950pro (make sure you have 2 crossfire bridges), it would give you more even performance over the three monitors and cost less (because you only need to buy oen card and possibly a new mobo), buy any 1950pro, they'll all work together,make sure you have a crossfire supporting mobo (like the 975X, or RD600 or X38, possibly even P35 because of bus optimizations in the chipset)