If your bun isn't exhibiting unwanted hormonal behaviors like humping and spraying, and you don't have any current plans to bond him with another fixed rabbit, there's usually no rush for having to get male rabbits neutered. They aren't as prone to reproductive cancer as female rabbits, so there isn't that pressing need. Really the only reason to get a lone male rabbit fixed is if the hormonal behaviors(and smell) are driving you nuts, which they most certainly can do. Otherwise, if I wasn't bonding then I wouldn't bother having a neuter done.
If you do decide to get him neutered and cost isn't an issue, find the most experienced rabbit vet you can. And if you get pre surgical blood work done, have a vet
very experienced with intubating rabbits if it's determined intubation might be needed(was for a dwarf rabbit of mine), and have an IV in case of complications in surgery, these can all up the chances of a successful neuter.
https://rabbit.org/vet-listings/
http://www.bio.miami.edu/hare/opcare.html