This is what I could do.
I'll bet that there is something in Apple's terms that would not permit a company doing that.
You also would have to consider the fact that anyone having an iPhone on the ONE account, would be able to purchase anything in the Store. With 25 users on the same account, that could also get expensive very quickly if you can't trust all 25 to NOT buy anything. And, you wouldn't be able to tell who, of the 25, was disregarding the rules and buying Apps, or iTunes.
What a Bag Of Worms that could turn out to be.