I've been happy with SmugMug, although honestly I've been idle with them from 2009 until just recently when the photography hobby got restarted.

I'm pretty sure you can link directly to a picture hosted on SmugMug, and then with one of the business plans you can also setup the e-commerce side to sell the print to the viewer. A basic account starts at $40/year, but I believe the business plans get upwards of $120/year or higher. I've not had any issues with the service and know a few other photogs who've used SmugMug as the foundation of their online sales, I just haven't established myself to that point to have first hand experience beyond that of a basic user.

Hope that helps.