I would definitely reccomend hisky. Easy to use, runs from a mod folder (so it doesn't replace core files), and it has pretty much no lag. I've loved it since I got it (And if you want, there are some custom water textures out there that you can put in with hisky so it automatically installs them. That's what I did.)
Hisky all the way, especially for 56kers! (Cuz its small. Did I mention that?)
And thanks, Cameron, for gloating about your system specs! You made me cry! Say you're sorry!
But seriously, I really want to take that computer off your hands. ;D