Where to get a supergun?

Where can I get a Sigma or Raiden quality supergun?!?
Unless I can find the harness for the one at the Neo Store, which seems to be even harder!

Does someone out there build very high quality guns?
It could just be the gun since my board uses neo joysticks.

try for a supernova at <a href="http://www.massystems.com" target="_blank">www.massystems.com</a>

i can build one and it'll be less, than a super nova.
send me a pm, if you're interested.

I really want a Sigma or Raiden more for my collection.
I have a cab, I just really want to own a japanese supergun.