I chose the Les Paul Junior bridge for its simplicity and easy
availability and because it can be adjusted higher than the usual
Fender-style bridges. There's no extra stringholder
required, and for mounting the bridge you just have to drill two
holes.
It has two features which are not required on a lap steel guitar:
(a) it is radiused, and (b) it has a (non-adjustable) compensation
built in. This compensation can be corrected (if necessary) by
holding the steel slide parallel to the fixed saddles (instead of
parallel to the frets). There isn't any adjustment
possibility to get rid of the 12" saddle radius, though. I
solved the problem by filing small notches into the saddles of all
the strings except the 1st-string saddle. Cut the notches with nut
files and deepen them until the tops of all the strings are at an
equal height.