Look at the ROTC room and board sticky here to see some options.
For example, TAMU will charge IS if you get 1K in merit from them. If my memory serves me correctly, being part of the Corps will get you that 1K. In turn, AFROTC will allow you to use that type 7 even if you don't live in Texas.
Personally, you are chasing the bucks, and that does not always equates to being happy at college.
Plus, you are impo a little late in the game from an application aspect for any college that offers that IS for ROTC students. On top of that AFROTC scholarships are not 4 yrs., it is 2+2. You need to get selected for SFT to get those final 2 yrs. What will you do if next year you decide you don't want to be in AFROTC, but love the school...how will you now pay OOS? What if not selected for SFT and they disenroll you...how do you pay that OOS or R&B if they only give a discount to ROTC students?
I would disagree with one point that Non Ducor stated. It is not the scholarship coordinator typically that can answer the question about being charged IS or OOS, it is the Bursar. Now for me, I would skip both of them at 1st and contact the det. directly to ask that question. They probably have AFROTC type 7 within the unit and will know if they converted to a type 2 3 yr.