I agree with Gwynzer, we need players who have interest in the game, if we don't, there's no point in hosting a server. We also need someone who has enough time to organise things and make sure everything keeps running, this was clearly lacking in RenX, because our server probably failed to show up in the listing for quite a while until it was noticed/reported, and I'm not quite sure whether it did in the end... Either way it wasn't updated so if it did it wasn't really useful anyway.
If we don't have someone with enough motivation and time to lead some section and at least some interest in the game for existing members, imo, we shouldn't replace the RenX server with anything else. We can reconsider RenX maybe, since it improved a lot over the first public build, but I don't see anything else potentially working out...