I finished a highly portable grinder stand this last summer.
It's powder coated for durability, employes sealed ball bearing casters with rubber tires and has adjustable rubber pads on the bottoms of all three feet.
Lots of pictures and more details than you would ever want to know about it can be found starting here on page 277:
http://www.garagejournal.com/forum/showthread.php?t=51567&page=277
See post #5528 and then continuing on the next page, 278, see post #5542. Take a look, I hope it might help.
Thomas from the Restored 1930's Auto Shop
http://www.garagejournal.com/forum/showthread.php?t=51567