Well, my advice - start with a pair of $24.99 Unidens or some sort of lower range walkie talkie. See how much you use them. I think these are good for short distances and sometimes within buildings, very unpredictable out it the woods - line of site only. Frankly I don't find the range estimates to be helpful, you might hear someone clear as a bell miles from the trailhead, or just static a hundred yards up a hill. And the GMRS don't really do you much good unless you're in an area with alot of talkers. If you intend to talk to someone in a BOB type situation, stick to a common channel, if there's chatter there jump up or down 2 channels. Having NOAA weather channels is always handy. Keep it simple. A couple handsets that run on AAs is all I would suggest.

Squeezing distance or performance out of walkie talkies will only get you so far, better imo to invest in a ham license and HTs with some real reach, especially via repeaters.