If you're happy with twin pipes - I'd opt for the LV's based on price alone. You'll get best results with a K&N/DNA air filter and either Kev's fuel mod or the Power Commander.

If you want an even better look, go for a single can.. X Racing of course..

Removing the snorkel (I just cut mine off with a Stanley knife and re-formed the inlet shape a bit) will also be a free enhancement to both power and a nice induction noise..