Hello,
It might sound weird, but I have 3 660 ti cards, which I bought for other CUDA related stuff, and I am not sure what to do with them.
660Ti are excellent miners, also for Yacoin. The three cards together do 10kHash or slightly more.
by all means put them to good use. Pick a 3 slot gaming mainboard, e.g. GA-990FXA-UD3
a cheap Sempron CPU and a 750W PSU and mine away.
you could earn about 10 Euros a day with power costs in the order of 2-3 Euros/day,
getting return of investment on the mainboard and additional components in about a month.