This is a common topic in the "Hardware and Performance" forum http://moodle.org/mod/forum/view.php?id=596
You can search for 'hosting' there http://moodle.org/mod/forum/search.php?id=5&words=hosting&forumid=94
Comparisons and advocacy
External Moodle Hosts
This discussion has been locked so you can no longer reply to it.