Yeah it depends what you want mate i agree with lufc. Duo chip is great for just gaming. If you want to take it the extra mile get a matrix infinity it adds lots of extra cool things. i.e multi region dvd and direct booting for any game! no boot procedures!
I have had both chips and i liked both equally the end of the day its your budget. As Duo is cheaper than the matrix infinity. Have a think about it.
www.duomodchip.com
www.infinitymod.com <---- Look here to give you a helping hand.