I'm not sure why everyone's trying to make their iso so huge. V1 has ATC, V2 has a ton of mediocre holdings (the only hand in his range that dominates us is AJ/KQ, and those are both discounted some), and we have position on both of them. We WANT to price them in to see a flop. This will both allow us to get more folds on the flops we miss and allow us to still have some dominated hands in their range to get a couple of streets of value when we hit.
If we iso to $18, then the players who have position on us are going to have to cold call $18 to see a flop with an SPR of less than 1, so lol at them having position on us really.
Raising to $25+ makes them only likely to continue with the hands they like (aka, hands that are doing well against us and are going to be stickier on the flop), and gives us really slim SPR's, which really cuts into our postflop advantage.
EDIT: Also, I don't think this is a raise/fold spot. I think raise>call>fold. It just so happens that once we acknowledge that our hand is far enough ahead of the two villains' ranges to be able to profitably call, then why would we limp behind when we could iso?