I want to buy a Coote. My next door neighbor and landlord is an electrician with good scavenging skills. I asked him tonight to start looking for a motor for me. I also told him I want to see if I can find a VFD. He said, "Oh, a freq? Yeah I'll find you a good one." Guess I should have spoke up sooner.
If you don't mind waiting on parts, you should build an AR. It's a lot of fun and you end up getting exactly what you want. Be careful though, modular firearms are pretty much like oxycontin for gun nuts. I built one a couple years ago and now I want to build another. Again, tools first.