Okay, this is my first build and this may very well be a total noob question here. I'm looking at MI quad-rail forearms and they have a two-piece that is M203 compatible and two-piece free float that is a little more expensive, but just looks schnazzier. I'd like to get the free float, but I do intend at some point to mount an M203 on this sucker, too. Will the free float inhibit my ability to do this because it has the lower rail?

Use a rail mounted 203.

Thanks, didn't even know they made those. That settles that.