Doug, I use two 9" front vises and a 12'" tail vise. The tail vise is only used when I have to clamp some long wood using the dog holes to hold it.
So long as the vise has guides to keep it parallel and a set of soft wood jaws you are good to go. Both the 9" have I believe 3/4" guides so it is pretty sturdy. The one vise also has a quick opening and closing mechanism that helps opens and closing faster. It is like a half-nut that flips in on the square threads.