an alternative to the previous answers (
not to say caelum is a bad option):
it's
very easy to self-host a server on a VPS, especially if you are on a budget (or no budget)
you can use the free tier on amazon aws for 1 year (which is entirely free) and host a server. (
miso knows a lot about this, or pm me for help)
also, I have a VPS with pretty good specs (way over what is needed for a jk2/jka server) and an insane amount of bandwidth (like 8tb per month) for about $20
a year.
Miso made a tutorial for hosting on linux here:
viewtopic.php?f=44&t=484
It's very straight forward and if you can't figure it out, there's a lot of technical people here to help
(very depending on your computer abilities lol)
Overall:
If you're on a budget, I'd recommend the VPS route as it's easy to set up, a lot more affordable, and you have basically complete control over your servers (once your first server up, the rest is a breeze and will be from that point on). You can be hosting a jk2/jka server on the same VPS and pay the same rate. In my opinion, if you have a brain and willingness to learn a bit, this is the better path if I were asking this question (not to mention support from quite a few people who already do this). This site has TONS of amazing deals, but you need to do some research because some are sketchy:
https://lowendbox.com/. But then again, definitely try out AWS because it's free if you are going this method. If you do prefer this, then get a VPS after the 1 year trial ends or you just want to spin up a lot of servers at once.
If you absolutely hate computers and are terrified of any command prompt/terminal command, definitely do not bother with a VPS. Caelum's route is obviously the better choice here. You'll probably get near instant setup and uptime you never have to worry about. (disclaimer: I know nothing about the service and have no idea what it offers). So go with this option if you are lazy, computers scare you, or you just want to support someone in the community (jkhub is pretty cool).
again, just presenting other options ¯\_(ツ)_/¯