Not too sure about artbooks, but im making one myself and going to try out Ka-Blam for printing. Im hoping they are speedy, unlike comixpress (which I do not recommend for any type of artbook because delivery can take up to MONTHS and the quality is very very flimsy) But I saw someone on DA that made an artbook from ka-blam in magazine size and it looked pretty nice! c:
I have not had personal experience, but Lulu.com is an option possibly. Also, Amazon.com does Ebooks, too I'm pretty sure. You should ask [link] She collaborated with her husband on an artbook project, which I purchased from Lulu.com