Paul,
I've said this before, but if you are looking at alternatives, don't get voodoo'd into any hype about hosting and forums. Not that you would, but there's a lot of hosts out there who really don't give squat about their people.
I'd be going with your own hosting somewhere. Sure, it's a hassle because you have to take care of the forums, but given it'd most likely be Apache you're running on, plus PHP and MySQL .. it's as likely to have as much trouble as the other 5 gazillion other setups like it

(read: not much).
There are some very good hosts out there (Media Temple -
www.mediatemple.net - is my goto at the moment) amongst the trash. A good way of finding them is to surf round the top tech blogs and see what people are pimping .. anything with more than a few people blinging is probably pretty good.
Anyway. Blah. Hope you get this sorted without too much hassle.