Exhaust tips don't do anything except make your car sound like a lawn mower.... I mean that's what Hondas are for after all.
The L intake is a great idea but I would make sure to put in a heat shield or find some way to get cool air to run over the intake.
And the air restrictor mod is another good idea, cheap and easy.... what more could you ask for?
More free flowing exhaust is one of those things where if you don't feel bad about dropping the money, it's worth it. It'll sound nice (assuming you do it right) and it'll be more fun to drive (In my opinion) There's lots to do, scour the forums, you'll find some.
An exhaust tip is dependant on what is in there. I've seen some exhaust tips with built in mini glass packs and I've seen some exhaust tips that are just a piece of metal used for looks. After all this is what the factory exhaust tip looks like on an R/T. :biggrin: