Well to get started you have to understand what's out there:
If you want something thats been undetected the longest, look into radars. I know a couple out there include Clutch Solution, Damncheaters and I believe Slate Hub. They have a 2d radar that runs either on your same pc or if you buy a piece of hardware called DMA you could use that as well. Some of these providers have a 3D ESP as well that shows outlines. The radars can filter look and show all PMCs/scavs whatever you need to see on the map in real time. Keep in mind there is no aimbot, and other carries will go into labs with aimbot to guarantee they win the raid.
There are lots of public cheeses out there with aimbot, ESP, etc. in the Black Market in epvp, and if you decide to look into those be sure to research the thread for vouches. I will also link a thread by a long-time trusted epvp user that shows which providers are legit/unlegit, so be sure to check out what he links.
If you choose to use anything other than a radar, I would 100% look into getting what's called a spoofer, which changes the values of your PC hardware so that incase you get banned by BattlEye, you wont be HWID banned. A HWID ban will prevent you from playing again on your pc, regardless of your account, until you change your hardware. Thus, a spoofer prevents the need to replace hardware, etc.
I would recommend looking for the slotted cheats, those tend to stay undetected a little longer since there are less users using them, and this is one of your concerns.
This is getting kinda long so I'll leave it at that, but feel free to ask me questions on discord as well.
The legit/unlegit thread: