You can find the 4" stop/turn/tail LED lights in many places. For me, I liked the ones which had a lot of LED's in the housing. I ended up going with Grote 53312 Super Nova with 24 LED's. It's American made and hermetically sealed. The Grote 4002 is basically the same light, but not hermetically sealed. The 53312 takes a proprietary pig-tail assembly where the 4002 is a standard type connection.
For the reverse lights, I bought some 2" clear LED's off Ebay and mounted them into my tire carrier. That almost ended up being a major issue as the tire carrier is re-enforced on the right side near the hinge with 1/2"+ c-channel and the hole saw didn't want to cut it. I ended up taking the plasma cutter to hollow out a space for the passenger side back-up light.
The side marker lights in the rear came from Northern Tool, they were ~ $5 each.
The license plate light is the only non-LED, and was a basic license plate light from Advance Auto for ~ $10. I had to mount it on the bottom facing upwards as I really didn't have any other space. They do make some LED license plate lights that double as the bolts which hold the tag on. These would have worked as well.
One thing I would say is that you may also want to consider some of the lights out there like the Gen-Right, which have the back-up and side marker lights incorporated into one assembly, similar to how the factory light is done.
I really like mine, but you take the neat all-in-one package of the factory light, and break that up into three or four individual lights (stop/turn/tail, side marker, reverse, license plate) with all of the associated wiring. When you consider that, the increased cost of the all-in-one LED assemblies is quite as bad as it first seems to be.
You will need a 4 1/2" hole saw in order to make the cut outs for the main lights.
I also have LED lights for the front turn signals and side marker lights. This was a Gen-Rite kit.
Here's what the finished product looks like: