I would sign up with any conventional shared plan but with a company that also offers a range of other services you can grow into: VPS and Dedicated hosting, so the switch is managed easily and without issues by same people.
Image/file hosting type of sites tend to grow quickly, so you better be best prepared. I doubt you want your hosting company to suspend your site if its using too many resources, which is why you can work out a deal that if its using more resources than your existing plan, they would automatically bump you to the next recommended package/solution.
What sort of budget do you have for this? I think that you may be better off starting with a shared hosting account and then upgrading as needed
With a budget of 50-100USD you can get already a good VPS. But look for a provider giving you the possibility to upgrade easily either to a bigger VPS or a Dedicated Server.
You think Hostgator would be a good choice? If not would you please suggest some good company's? =P
Do you need this VPS to be managed or can you manage it yourself? Perhaps we can help recommend a few providers to you
I would use shared hosting as your site grows in popularity you can upgrade.
I would use shared hosting as your site grows in popularity you can upgrade.