RE: i need help
I can only speak for myself but my 27mhz FM has worked flawlessly and trust it as much as radios can be trusted.
AM radios have a lot of problems, and are pretty much obsolete now so those are a bad investment.
Just be sure to use a fail-safe on your throttle whatever you choose. Thats the best insurance and they are not very expensive or bulky. More can go wrong than just loss of signal so it covers that aspect also. If anything radio related happens the fail-safe chops the throttle for you.
The worst that can happen is you're stuck having to retrieve your boat sooner than you wish, but your happy it is not in two or more pieces when it does happen.