I have the later style window regulator, but have found that other than the roller that goes in the window channel on the bottom of the glass, they were in good shape. The scissor style that the 47-50 trucks use have a few more wear points, but you may find that your originals are good to use other than the rollers.
I don't have any experience with the repop regulators, but if yours is serviceable with out much work, I'd stay with the originals.
