Where can you get a p90?

Answer 1

Well, first you have to live in a state which will approve NFA Class III transfers. Then, you have to get a Federal Firearms Licence... Type 1 (dealer) with a Class III Special Occupational Tax Stamp is the one you'd probably want. Once you've done that, you'll need to open a store front, and you'll probably need to build and open a range in order to justify the purchase (purchasing it for range rental). Then, you have to obtain a letter of approval from your local law enforcement agency which authorises you to purchase the P90 as a dealer sample.

If you don't want to go through all of that, the most you'll manage is a PS90. It's a semi-automatic variant of the P90 with a 16 inch barrel. Any FFL dealer in any non-AWB state can order one for you.