My %@#$!'ing session timed out after typing out a lengthy (and informative) post on this so here's the highlights. ;)

An erotic gallery will put you at 500meg to 1 gig of traffic.....a day. I speak from experience with a site that has only been up a couple months now.

Canaca will host any legal content... as long as it doesn't exceed %10 of the server machine's resources. An art site will easily surpass that. Almost all hosting sites have a clause similar to this, read the AUP or FAQ. If you don't see it, call and ask.

I couldn't find the hosting info at cheapbandwidth.com, just searches of other sites offering hosting. Where is the hosting info pertaining to cheapbandwidth.com exactly?

The best place to ask any other hosting-related questions is a web hosting forum. Try http://www.webhostingtalk.com, a wealth of information. You can read host reviews, check prices, look for server sales, etc.

Good luck! :)