I agree with Wes for the most part...
I used a VX7R for a year + as both my mobile rig and my HT. I ran coax (the thin stuff) up to the front from a rear mounted antenna and would connect up the HT there...I used the external mic/speaker combo (Yaesu MH-57A4B) and found it to work just fine. The biggest issue was the limited reach with just the 5W max that the HT puts out. It was GREAT for trail runs, but around town or on the way to the trail I just couldn't reach as far as I wanted to...
Now I'm running a FT8800 as my mobile rig and I love it.
Sounds like you "need" a HT for when you are out on foot so buying a HT won't be wasting money should you discover that the HT just isn't cutting it for when you are in your Cruiser and decide to upgrade to a true mobile rig later like I did. About the only extra (i.e. wasted) cost might be the coax run from your antenna to the HT depending on your setup. I have the Diamond K400CNMO mount on the rear hatch and used the 10' Diamond C110SMA extension to reach the front. The nice thing on this was that both the mount and the extension are the thin RG316 coax so I didn't have to futz with any adapters/connectors...Plug the K400CNMO coax into the C110SMA extension and then that extension plugged directly into my VX7R.
The bonus of upgrading to a true mobile rig later and still having the HT is that you could set up the mobile rig to be a repeater when you are out on foot and that would extend your reach with the HT by a lot (as long as you could hit the truck from where you were).
As for what HT to get...I've only ever used the VX7R and it has been great. I think they are all really comparable so figure out what features you really need to have and buy one that offers those features.
Jeff Z. (the "not quite as skinny" one)
'97 FZJ80 Antique Sage AE #267, stock
12/74 FJ40, 2F, SM420, 4" Lift, ARBs, 33" MTRs
"...anything else i can do for you guys, how about i wash your car or mow your lawn while you figure out your firewall system? I am now boarderline insane/unibomber." Kipper
"That assumes I'm even capable of pulling and stabbing..." Jacket
"I really like having a detachable unit." Beater