I need a vise and am not sure what to get.
Price is a consideration.

My mill has 4 of the 5/8 T-slots, T-slot centers are 1-13/16.

A friend has some table width bar stock on his milling machine, with a solid bar in the rear slot and one with square head bolts in the front one that he cranks down with a speed handle. It's a slow method but it works, kinda.

What is a relatively cheap/good milling vise, in the 4-6 inch range?