ECU Flash from Ivan's Performance available

[Toku57]

Ideally, if I get a Voyager I'd like to find one that's already been Ivanized. However, if I can't I'm wondering if you all could answer some questions about how to proceed in the most economical manner:

I see where Ivan charges $350 for the re-flash, shipping not included. If I got the re-flash done and decided at a later date to get some V & H slip-ons and a Roaring Toyz air filter or similar products, would I need another reflash?

Also, Chuck A. mentioned he's considering getting some slip-ons from Ivan, so I'm assuming he sells them. Does he also sell air filters, and is a bundle deal, i.e. getting a re-flash, slip-ons, and air filter from him a better deal than getting the slip-ons and air filter somewhere else?

Since I definitely would want the ECU reflashed, and probably want slip-ons and an aftermarket air filter, I'd probably just budget for all three unless I was fortunate enough to find a bike I liked that had all three. But if not, it'd be nice to know the most economical way to proceed.

Final question about aftermarket air filters. Do they make much difference to the decibel level? I know they can make inline 4's and 3's noticeably louder, but wasn't sure about V-twins. I wouldn't want the decibel level to be a lot louder than stock, so if the slip-ons/aftermarket air filter combo makes the bikes considerably louder I'd probably just get the re-flash and slip-ons.

Thanks in advance for any guidance here.