It really does not matter who Freepers prefer as the Republican nominee.
The media will decide by virtue of coverage volume:
1. pushing(McCain).
2. degree of personal/political destruction (Newt)
3. character assassination (Newt and Rudy)
4. Right Wing Extremist (Santorum)
5. Marginal religion (Mitt)
6. Militaristic (Duncan)
Interesting theory but it has one flaw: if McCain doesn't get the nomination you're theory isn't worth a hill of beans. Because as you say, the media will be pushing McCain all the way.
And I hate to break it to you (seeing how it's going to wreck your theory, and all), but McCain is NOT going to get the nomination.