You need a large pool of ticket buyers to have a successful raffle. The raffle also has to be legal in the state in which it is conducted.
I think it would be difficult to hold a successful raffle for this in your small farming community. Raffles work best within large communities that are related to the cause. If your son's office is not large enough, maybe there are co-workers whose churches would be willing to help raffle off tickets? You mention the word "stationed"; if this is an armed forces unit, I would think that would work as a large community related to the cause.