I just bought the .410 Tamer a couple of weeks ago. I love it, shoots nicely, super small. For the $170 I paid, it's a nice little banger. One problem I do currently have is that it only likes Winchester ammo, whether it be slugs or shot. For whatever reason, it refuses to automatically eject any federal or Remington shells after being shot. I just use my truck antenna to push them out....oh how I love field engineering solutions. Maybe take this information with grain of salt however, because I have yet to clean or lubricate the gun.
It is quite loud as well, allot louder than a pump action .410.
I think your going to have a beyach of a time finding a pistol grip for it. I haven't looked because I like the size of the gun out of the box, (if you haven't seen it, it is super small), also, I would be concerned about turning your small, single shot non-restricted shot-gun into an extra small, restricted one. Keep in mind it has to be over 26" (I think) inches to be considered non-restricted. I measured mine and you could still legally cut of some of the synthetic stock to about the end of the shell holder. Not worth it in my opinion.