Will, funnily enough I have been looking at the Delta as well, but its mid engined so space may be a problem. (says he who has jus put a huge console in a P22). Daves P24 has the console sat at the back of the boat on the engine box which gives loads of room at the front for divers and if i was just using mine for diving that is the way I would have gone. Six is with twin sets etc although I think it was propped down to 20 knots.
The only downside to a P22 is divers won't be able to climb over the tubes to get back in as they are bigger than normal and out of the water at rest. Not a desparate problem as they normally climb over the transom instead and the stern drive makes a good step. However I agree a Pacific with a TD is the way to go and at sensible money.
You could probably get Fills for a good price if your after a Pacific.