I'm not sure, but I recall kingsnake.com's gallery having a premium service for larger space... I haven't looked in a long time.
I wouldn't get a "photo/image hosting" service at all. You'd be better off just buying a domain name and webspace so you'd have full http/ftp/ssh capabilities. A lot of them come out to the same price give or take, and in exchange for a little difference in price you can make a whole site of whatever you want. And with the space you could hold copies of important documents, etc.
Where ever you go, just make sure they allow off-site linking, that's what matters: the ability to refer to specific files on your space/site from anywhere on the web.
Personally, the University of AZ gives me a very generous amount of webspace as a CS major.