Whats the best anticheat? Free or affordable.
There isnt a “best” anticheat, that’s outright a weird question. I highly suggest you look into using Badger’s AntiCheat for a start - it has all features you might need. Just dont ask dumb questions on the thread, read the documentation first 
But do you know how to make it possible that admins can use noclip with invisibility? I already use the Anticheat.Bypass but it still doesn’t work…
I dont know how your admin system is set up, so not really. Figure it out yourself - ACE permissions is very simple, just time-consuming. Make sure you follow the documentation of the anticheat, it’s all explained in great detail there.