Your money should go into the antenna setup. It makes the most difference in how well the system works.
I had a Wilson 5' Silverload fiberglass antenna and it broke off at the base on the first trip out with it. I then got a bottom loaded antenna and that didn't work at all where it was mounted on my Cherokee (midway up the rear gate). I finally swapped to a 102" whip on a solid 6" extension and got a 1.1:1 match, 5 good years of use from the same antenna, and the SoundTracker feature on my 18WXSTII Cobra worked for the first time ever.
I have a Uniden 505 in my K5 with a ball mount on the bedside and a 102" whip and heavy spring. Again, good preformance, excelent durability and never a bad report on the trail.
IIRC, a top-load like a Wilson Silverload has a lower radiation angle than a bottom load or 1/4 wave, but I managed to talk about 12 miles off the weak side of my Cherokee (mounted on rear gate so radiation pattern was towards front of vehicle. I was talking to a station in the opposite direction I was driving) and was able to easily carry on a conversation. Off the strong side, I'm not sure how far it would go.