I just installed Bilstiens yesterday with original springs, and did so persuant to research with Expedition Exchange, Atlantic British, several d90.com users, etc., that stated that the OME springs are matched in length with OME shocks (longer) and the Bilstiens are the SAME LENGTH as original shocks. If you fit Bilstiens with OME springs the shocks will inhibit travel and articulation. If you fit OME shocks with original springs, the rear springs may unseat due to the added length of the OME shocks.
Original springs = Bilstiens
OME springs = OME shocks
I suppose it is possible the Bilsteins are limiting my downward travel, I never really checked. But I still get the benefit of additional lift to fit larger tires. And until the rear sway bar comes off, (which mine is) it will prevent downward travel much more than the bilsteins.
So I think the answer to his original question is still no, in that he won't 'have' to get new shocks. He *may* want to though :grin