Ask HN: Recommend customer-facing forum software / SaaS for startup.

Hey guys. I'd like to host a forum for our users to be able to chat with each other, propose new features, help each other if they're having issues, sticky a few posts here and there as FAQs for them to reference. We're getting a lot of customer support requests these days and they're too many to handle for a team of two, so we're better off addressing them passively through FAQs and self-serve a la Google.

I'm thinking I'd either host this myself or I'd pay a SaaS service to do this for me. The latter is preferable, since setting up configuration management to deploy and backup the forum is a pain in the ass I'd rather delegate to someone else for a few bucks a month.

Some candidates I'm thinking of:

Google Groups - nice, but no way to sticky anything UserVoice - not quite a forum unfortunately, mostly a direct communication channel with the company. A subreddit - I don't know if I'm totally comfortable relying on an external service (that I'm not paying for and thus might be down for random periods of time). Discourse? Disqus?

Anything you guys would recommend that worked very well for you?