According to Orthodoxwiki
he is glorified as a saint. As for taking a new name, there are indeed various opinions on that, and really even more options that you mentioned, so it can get complicated.
- Take a saint that you were named after, with no deviation
- Take a saint with a name you were given, though not necessarily the same one, or even necessarily a universally recognized saint)
- Take a saint having to do with your birthday or reception day
- Take a saint you feel attached/attracted to, and be called by that name (for communion, etc.)
- Take a saint you feel attached/attracted to, yet be called by both that and your given name
- Take the name a priest/random person suggests.
- Make one up based on an already existing saint of the opposite gender