Finishing a Rig, need a good Memory Card

[DukeSilver]

Hey everyone, thanks for accepting me onto The Scream!

I am building a computer for my little brother as a way for him to stay in touch when he goes of to Uni, and I have it all finished except the video card. I need to get a used one as I spent most of the budget for his little gift on the processor and the liquid cooling system. I was thinking of getting him the Titan as I am pretty sure that telling him something called Titan inside his machine he would love it. Crazy kids

Anyways, does anyone on here have any suggestions as to what video card would work best with an early i5 processor, an MSI Tomahawk MOBO and Corsair liquid cooling. I have two slots, so a couple older cards would also work.