Exposurer Manager is the choice in most areas for what you're looking for - and by areas I mean prints, price, etc. They are meant for event photographers uploading and selling online - unlimited storage with the event account, you can set it to "display only' or "print ready", etc. To costomize you need a bit more knowledge with html (or you can just use there basic set up). You get costom headers and footers so can integrate your own site pretty easy. You also do have that nifty referal plan mentioned above for a 15 day trial, and hey why not - mine's...
www.exposuremanager.com/aff/mikejanesphotography
Photoshelter also uses EZPrints, in other words I won't touch them for prints though I do have a membership that I pay for and don't use yet. Gavin just won't build my site for me, geez!
(seriously, his site rules, and I just can't figure it out yet though I've tried - soon, soooon). Anyways, reason I have a membership with them is for a database of photos so MEDIA clients can download from there for print purposes, it won't be used for prints. If a player or someone goes searching and sees a photo he can email me and I'll direct him to Exposure Manager and set up a page for him to go through. I don't like the limited storage of PhotoShelter, I have to resize all my pics to put on there and that's why it's not up yet.