GP or NGP CB antenna on 1st gen

I have my CB ordered. Now my only question is GP or NGP antenna?

A few specifics:
1st gen tacoma (so metal bed)
Planned mount location: Rear drivers side of bed, mounted similar to this, except with quick disconnect attached to mount, with spring and antenna on top of that to allow the spring to rotate in any direction:


Bed is bedlined(not sure if that makes a difference.)

I'll be using a 3 or 4' firestik.

I did a little reading, though not a ton. I understand NGP antennas are meant for vehicles with little to no sheet metal surface to bounce the RF signal off of. My question is since my planned mounting location is less than ideal, with not a ton of metal to radiate the RF signal off of would it be worth it to go with a NGP antenna. I'm not looking for anything fancy here, just the ability to communicate while on the trail. I see most people just use a normal antenna without issues. However, if i'm going to spend money on something i'd rather spend a little more for a more functional unit. Again, not looking to communicate across country here, a few miles at most.

Thanks, and sorry for any unintended noobishness that may have been included in the question

 

NGP antennas are poop. You will be fine with a regular Firestik.

 

Bump