The Mission Ranch area of Riverside is as you've pointed out close to March Air Force Base (March Reserve Base), however the area would typically attract move up buyers. If you are truly speaking of Mission Ranch proper, this area carries some very high mello-roos.
I would imagine that if property that you are speaking of is undeveloped, then you may be in a rural area just on the outskirts of Mission Ranch. If that is the case, then you would be looking at a much more broad range of demographics.
There you will find home buyers looking at a variety of uses for the property, from low entry level home to horse property.
Dependent upon the exact location, I can assist you with the specifics of the area. I also have a client that has been looking for a special use home in the area and that may be the perfect client for a custom build for you.
Please contact me directly and I help you though the specifics of the neighborhoods so that you can determine your best scenario.