I was wondering if I could set up an SLI with 2 'damn near' identical cards. They are both GeForce GTX 470's, but they are made by different manufacturers and have slightly different clock speeds. I put links to them below. Also, if i can set up the SLI, would I have to match up the clock speeds? This is the first time that I am going to set up an SLI, so any advice would be appreciated.
I can't view the two cards, but yes, two same-model cards from different manufacturers will work.
As for your clockspeed question, it used to be so that one card would downclock itself, but I'm not sure if that's how it works. Preferably, overclock the other card just the little bit you need to match them.