LCoop, I think you are just a little ahead of Northridge Tools at this time--they will have all those options in about 4-6 weeks. Sooooo-if you really want to go ahead and get your grinder (which I totally getz) here's what options I would look at. First, you should check out the AMK grinder--AMK Tactical, you can find them on the web, they also have some grinders listed on the Bay. Their grinders are really solid, they have a flat platen and a contact wheel on one tool arm--this arm pivots and stays in place on the grinder-you just pull the pin and loosen a couple of lockdown knobs and turn the arm over. If you want to mount their small wheel attachment, you have to back two bolts out of the pivoting arm and pull the flat platen and bolt on the small wheel attachment. The principal, Allen Poe is a great guy, and he will outfit the grinder however you want--i.e. I got a 3HP Leeson motor and a KBAC VFD(nema IV enclosure) I have been very pleased with mine. If you want a more traditional grinder in the sense that it uses different tool arms with the various fittings you want i.e. flat platen on a tool arm, contact wheel on a tool arm, small wheel attachment on a tool arm and so forth, then that's what you would get with the Northridge Tool unit, (but I know about the wait) so for that type of grinder, I would look at Pheer or Esteem grinders. I think any of the above would be great for you, I'm a fan of the AMK and the Northridge.
Good luck whichever way you go!!