Hunt for the Waves plug-ins. You can use them in Fruity, I think, and one is called 'maxx-bass' I think. This processes your bass sounds...

Muon-Tau is good - very 303 sounding...

Another thing you can use for bass is distortion - Fruity has some sweet distortion units, as far as I remember.

Basically, make two b-lines. One sub, probably on the off-beat. One higher up, which can be more funky.

Or the other way round if your kick drum fits...

Just use your ears to make sure that sounds don't overlap, frequency-wise. Good sounds can turn to mud if you're not careful! If it loses power, re-work it...

Tequila