I agree with BigEd, german pils will be a fine substitute and I've read some Belgian breweries use german pils. The only Belgian Pils malts I've used are Castle and MFB (OK, French but whatever) and I got lower yield form both than I do from Weyermann (Bohemian or regular) or Bestmalz.
I got clearerer run-off from the Belgian Pils malts I've used.
Malts very from brand to brand but one flavor compound in Pils malts that makes them different is the DMS, and it varies from brand to brand (and probably lot-to-lot and season-to-season). It's usually thought of as a flaw but in very low levels is actually a part of what makes many good german lagers. It's a sulphury/corn-like aroma. I seem to get less of it from the MFB than I get from the Weyermann. It's been a while since I used Castle but IIRC I got major 'popcorn aroma' when mashing so it might be higher. Long boils can greatly reduce it but often a noticeable amount is still there and it doesn't take much to notice it, especially in a clean lager.
