While on the subject of vises, I have a Palmgren 2 1/2" tilting vise that I find quite useful on occasion. It is not ridged enough to make heavy cuts, not precise enough to equal a sine plate, but for nearly any angle work that I do, it has proven adequate. Picked mine up second hand on evilbay for somewhere around $50 if I recall and have always considered that to have been a great bargain. You may wish to keep your eyes open for such a deal but beware that many of them out there are well hammered and abused, so wait for a decent one as they do come up occasionally.
On another note, you have probably already made this decision, but another important choice that needs to be made in selecting a mill is what kind of spindle nose you'll be wanting to mount what type of collets, chucks and other tooling.