I would almost be tempted to give them surface under polish. The polish will help the ball get down lane to combat for slower speed. The surface under will give the ball teeth to hook in the friction helping combat for lack of revs. I would try whatever ball at factory finish , Then make surface adjustments according to what is needed. But that's just my opinion.

In theory, if a bowler has slower speed and low revs, would they usually be better off with a strong drilling and a shiny surface; a weaker drilling and shiny surface; a strong drilling with dull surface or a strong drilling with a shiny surface? 

I know there are a lot of factors involved and all bowlers would not be the same,but in general, what would be your opinion for the above if bowling on a typical medium house shot.

Thanks.

My opinion is that you're going to get yourself in a ton of trouble living by any generality in this situation. This is due to both the wide variety of balls available today and the equally wide variety of oil patterns and transitions being seen today.

Add to that the fact that other bowler factors affect the length such a bowler gets from any ball: tilt, angle of rotation among them.

A low ball speed bowler has to retain energy, first, and second, the ball has to hit the right breakpoint area. Add all the factors that affect this, like ball surface, oil pattern, coverstock composition, drilling, etc., etc. and you have the normal complex equation.