rgp - I agree with not wanting a flip-up dodad...

the coolest option i've found for visibility (and some may disagree but) is the trijicon inserts.

Trijicon has a custom shop and for about 100bucks they will put trijicon in whatever you want.

The trijicon is not necessary for low-light shooting, but the trijicon is enclosed in (and visually surrounded by) a white plastic (or space-age polymer) line.

On a DR, I would consider having an insert put into your existing front bead, and a vertical line in the rear sight.

neither increase the size of the sights (visually) as would a flip-up front sight, but they are much more visible with their white outlines.

Basically, you have butch build your gun and he can send the sights (after the rear is filed in) to trijicon, or you can remove the sights and send them yourself after you receive the gun.