FT-857 will indeed do HF, 6M (lowband VHF), 2M (high band VHF) and 70cm (UHF). What you need to operate it is a General class ham license. You won't be able to legally use it for 11M, MURS, GMRS, FRS etc. Which is fine because dedicated radios will do a better job of all those things anyway.
I would (did) get used commercial radios to do the MURS and GMRS thing. For CB, you can find lots of threads on this forum discussing the relative merits of just about any radio you can imagine. For trail use, there's nothing wrong with a cheap Cobra 19. I have two of them, and they work fine.
Even aside from the legal issue btw, you don't need 100 watts for trail communications. It gets you more hassles than advantages anyway. And I'm not even talking about the legal issue. I'm not saying 100 watts is difficult, it just makes waaaay less difference than just about everyone assumes. All the while creating 20 times the heat and running down your battery 20 times faster.
I would (did) get used commercial radios to do the MURS and GMRS thing. For CB, you can find lots of threads on this forum discussing the relative merits of just about any radio you can imagine. For trail use, there's nothing wrong with a cheap Cobra 19. I have two of them, and they work fine.
Even aside from the legal issue btw, you don't need 100 watts for trail communications. It gets you more hassles than advantages anyway. And I'm not even talking about the legal issue. I'm not saying 100 watts is difficult, it just makes waaaay less difference than just about everyone assumes. All the while creating 20 times the heat and running down your battery 20 times faster.