When it comes down to it, Air Intake is a "Looks" thing. You just don't get a ton of power out of it, so don't do it for the power.
If you dig it, cool.. We can assist you with what you choose to put on.
Basically, you're looking at how much restriction you're removing.
The more you remove, the more modification you have to do.
Basic steps are:
SCAR Mod, 1 Shim
SCAR Mod, 2 Shims
Factory Pro Stage 3 Jet Kit
ALL Stock VTX's can use the 1 Shim SCAR Mod. Period.
Do a little something to the stock intake, then 1 Shim SCAR Mod. (Say, K&N Air Filter and a couple holes, Closed Spyker Mod)
Do a little more, 2 Shim SCAR Mod (Say K&N, Decap, and a Few Holes, or an Open Spyker Mod)
Go aftermarket (BAK, Big Sucker, Doug's, Spyker Open with a Decap and Holes) then you're looking at a Jet Kit.
PIPES DONT MATTER. Do not jet a stock bike just because you put pipes on it. This is a Heat Thing that AIR COOLED bikes need. We are Liquid Cooled, and don't have to worry.
But also keep in mind, if you go ahead and get a Factory Pro Stage 3 Kit NOW, that kit will do anything from Stock to as crazy as it gets. So, if you're "just playing a little now" you can Jet and Set the carb for that. Later on, if you go nutso on the intake, you will have the kit to Jet and Set it .
I also Highly Recommend Glen's Permanent A/F Tool ($40). It will keep you from pulling your bike apart again if you dont get the A/F Mix right.