WRWK533

No, not from the ground. Yes, I'd have to be pretty high though. 5 ish miles. Possibly, I'll need to check. Yes

Presently I just have a handheld, UV-5G with the stock antenna. I am willing to put up an external antenna and buy a base station, but not if it's going to bring minimal results given my low elevation.

New to GMRS still. I was wondering why I was having so much trouble hitting closeby local repeaters and didn't hear much of anything. I looked at a topographic map of my area and realized I live in the lowest part of town. By over 100 feet I am in a river valley. I have the option to put up an antenna on my house, but it would only be about a 5 foot antenna extending above a 30 foot roof. What is going to be my best bang for the buck in terms of improving my range?