For what you want to do I would definitely go with a dedicated server right off the bat.
I use
Cyberwurx and have both a VPS there and a dedicated server. I use them because they have the best support I have ever received. And they build very stable systems.
I have used pretty much every adult host and tons more mainstream. Cyberwurx outshines them all. Use 10TB on checkout and get 10 terabytes of bandwidth.
Also with any hosting company, haggle! The prices are more of a suggestion. Get them to throw in free 2 gigs memory or add some IP's. They will bend over backwards for your business.