Need graphic card help...please

I just bought new parts for a system build including a 1000w power supply, gigabyte Z68a-d3h-b3 and i5 2500k processor. I have a old EVGA GeForce 8800 GTX without a install cd which I would like try. I also have a ASUS EAH5770 in my current computer. Looking on newegg, the current ASUS card is:

ASUS CuCore Series EAH5770 CuCore/2DI/1GD5 Radeon HD 5770 1GB 128-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card. I have this in a midtower now and the gtx wont fit in that case.

If I do use the 8800 gtx in the new build, how do I install it without the disc.

I would also like anyones opinion on what they would do with the cards and my setup. I eventually would like to have dual graphics cards ready for diablo III by the end of the year.

Thanks