Adam, yes the 1.5" height is due to the cut springs not providing as much lift as un-cut springs (but they'll have a higher spring rate).

Is there a reason you want to use MD springs? The reason I'm using MD springs as my starting point is because the spring rate increases when you cut the spring, and I like the HD spring rate; so I'm basically turning the MD springs into a "shorter" HD spring.

If you want to drop down to the MD spring rate, you could run them un-cut in the 5100s; i'd probably try the middle lift setting and see where that puts you. If it's not high enough once everything settles you can bump them up to the highest setting if needed.

If you like your HD spring rate, and don't have any aspirations to run a modified superlift then you could just get the 5100s and put them on the lowest setting with the HD springs. I believes there's a few WK's running that setup already.

and just to completely derail us....Have you thought about the ICON coilovers?