Serverguard or ULX

Well if you can make your own custom administration add-on that'll be a more preferable choice. Usually asking devs to make us one.

On the other side, ULX is better. ServerGuard only gives you that "premium" feeling or effect, even from what I heard it has terrible support. ULX is free and usually gets updated and a lot of scripts supports ULX anyways. They're both really are the same except one costs money and one doesn't. So just go ULX.