Wheels are a great place to lose weight from, however if you have Rays on then probably not worth looking at anything else unless you've got serious cash to burn.
From a standing start, the tyres will be the other big place to make gains from. The quicker you can transfer the power down the quicker you'll be moving, so pick a semi-slick to suit your budget and go from there.
Aside from that, it's just going to be about weight as others have already said. Saving weight will be better than 5bhp extra from a filter, and cheaper too.