It's a pretty big task, if you're planning on taking it serious. An old acquaintance sends me (and everyone on his list) a long message containing fixes and updates almost everyday. I'm not a RSPS programmer, but I knew this guy from assisting him with teaching a small Java class. Compared to some of the other programmers I've met through the RSPS community, he wasn't that bad (although I wouldn't say he was all that good at the time either). After almost a year of receiving messages about updates and getting asked a few questions, I found his server on this site (Elveron), which doesn't look too bad by the images (haven't checked out the server though). I'm not sure how well of a programmer he is now, but that goes to show that dedication pays off.
If you ask me, I think the hardest part would be originality. With the proper programming experience, fixing bugs and cleaning your environment will be the easiest part. You should take it slow and first try to think of ideas for a UNIQUE server that's actually worth playing. Marketing is also a pretty big aspect, and if you market the same material everyone else is marketing, you won't stand out.
Like I mentioned, I haven't played Elveron, so I can't give you an opinion on the quality. If you want, I could try and get in touch with him so you can ask a few questions about what it's like running a server. Although, if you don't have the coding knowledge or have a really close friend that can program, I wouldn't bother. Unless you have top-notch leadership skills or cash to dish out, the developers might take over. If you do decide to create a server, I wish you luck, and you can always come to me for any programming questions you may have