If it's a remote RF deck, then install this behind the rear seat. Be cautious about putting it on the floor since that is where a lot of crap/moisture ends up and won't be healthy for the radio.
Skip the power poles. Over priced and won't do anything for you.
Check around the fire wall. You should find some feed throughs where bundles of wires go through. Look for a nipple on those that can be cut off and will allow you to pass the larger wire through. If not, you need to get creative with a fish tape. There's lot of descriptions on this site on how to do it. Use split loom tubing over your wiring to protect it. Make sure it's something that is rated to be in the engine compartment. This not only protects the wiring, but makes it look a whole lot more professional.
Positive should be connected directly at the battery terminal with a fuse as close as you can get to that. You want to protect the entire cable run.
Negative, use the body as the return. Modern vehicles are set up this way and many will tell you specifically NOT to connect direct to the negative terminal. Not sure if you year truck has that, but it's the right way to do it no matter what.
Ground the radio chassis. Yes, I know the negative lead will ground it, but ground the radio chassis anyway. It can prevent RFI and other issues. Super easy to do while installing. A pain to do later if you don't and require it.
Fuse or circuit breaker will work. I use these, you can get lower ratings for you need:
Buy Bussmann CB285-60 Surface-Mount Circuit Breakers, 60 Amps (1 per pack): Circuit Breakers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
Benefit to a breaker, is that it makes it really easy to disconnect the radio if you are not going to be using it for a while, letting someone else use the truck who shouldn't be monkeying with the radio, or taking it into the shop. Yes, you can pull the fuse, but the breaker is easier.
Most of your time should go into proper wire routing. You need to take your time and think about the path. You need to keep it away from anything hot and/or moving. You can follow existing wire routes. Use the split loom tubing to protect it and hide the cable. Looks way better in the long run. If you use ty-wraps, use the black ones, they'll do better in a hot engine compartment.
I really strongly recommend sealing all the connections/crimps with marine grade heat shrink tubing. It's standard heat shrink tubing with a hot melt adhesive on the inside. When heated, the tubing shrinks and the adhesive melts and flows over the connection. It'll seal out moisture. You can get trays of marine grade heat shrink at Harbor Freight pretty cheap, and it's good stuff.
No sheet metal screws for securing the radio. Through bolt everything with machine screw, nylock nuts and large fender washers to distribute the weight of the radio. Keeps it from bouncing around if off road, or on some of the finer interstate slow lanes.
Take a look at Magnetic Mics. Yeah, they are expensive, but really nice for mobile use. Much easier to hang up the mic without taking your eyes off the road:
Amazon.com: Magnetic Mic
www.amazon.com
We use these in all our police cars. I have them in my work truck and both personal vehicles.
Use an external speaker with the radio. The larger speaker really helps with audio intelligibility. I use the large Motorola speakers, you can get used ones really cheap. They are loud and clear enough that I can easily understand the radio traffic while running down the highway at 65mph in a Diesel pickup with all the windows down. The little speakers built into the radios kind of suck. You'll be impressed with the audio, makes listening so much easier.
And good on you for doing a proper NMO install. Too many people weenie out and go with some compromise mount. Do it right the first time, always pays off.