www.grizzly.com
I have the grizzly knifemaker sander. my feelings are mixed. Customer Serivce and QC are iffy at best, and it can take a long time to get it. I ordered in August, got in late October.
Machine runs pretty well, lots of power, but needs some mods. first, throw that graphite junk right off the platen. Then make a real platen for it
Tool rest needs to be squared up if you use it for anything, mine came so that it was 1mm from the wheel on one side, and 3 or 4 mm away on the other side, not good! Tensioning and tracking need to be played with; the belt they sent was I think about 76" long, not 72, but you can adjust for belt length. Make sure you have it on a stabile base as the arm is pretty heavy and can make the machine want to tip if you are grinding with pressure. Get Allen Blades video's with the mods he did to his Grizz in it.
Minus' to the grizz are no attachments. No small wheel attachments, so finger grooves are a pain. Speed is pretty damn fast and with higher grits, its very easy to burn steel. Very easy. I might try to mount mine with a pulley attachment to slow it down to 3 speeds, like half, 1/4 and 1/8 what it is now, wich is 3600SFPM.
You can also get the grinder w/o motor for $150.
I would go with Rob's grinder if at all possible. I know a guy who got one and loves it on another knife forum. From everything i have heard, Rob does great work and people are very pleased with it.