Earlier quoted context omitted.
5.8 is still currently in development/snapshot - not for amateur users. 5.7 is the latest official release. 5.8 is due on Nov 1.
Worth noting though that if you use the release, you get no updates, security or otherwise, till the next release in 6 months. And using -stable (release + patches) is a hassle of manually applying patches and re-compiling - no binary updates are available. If running snapshots is not for amateurs, neither is running stable.
Running -stable is fairly simple. If you don't want to rebuild on your DigitalOcean VPS, cut a new release after an update locally, and then apply it on your VPS. See http://www.openbsd.org/faq/faq5.html#Release. This should be fairly simple to automate (and you could even write a script that only packages up changed files if you were so inclined).