Short answer is yes. you will be able to run it to the rear cap. I have seen this done numerous times on law enforcement vehicles. However, how much time do you want to invest in wiring??? Most professional jobs involve removing the interior pillar covers and ceiling to hide the wiring....But if you are ok with exposed wires, then that works too.
With that said I wasn't familiar with the camera you are using so I went to their website and looked up. To connect the rear camera, they use simple coax cable which is a relief. They have two versions, a standard coax cable and waterproof coax cable in several lengths from 1.5 meters (4.9 feet) to 20 meters (65.6 feet) for the standard coax, and either 15 or 20 meter coax for the waterproof type. if the exposure of the cable from where it exits the cab to where it enters the bed is three feet or less, you can probably be ok with just the standard coax, but make sure you wire it so it's protected, such as with split loom. This will help keep abrasions down to a minimum. Also be mindful of where the cable enters/exits the cab and bed and use rubber grommets prior to feeding the cable through.
If you are unsure of how long of cable you need, my recommendation is to take some cord - like paracord and run the distance from where you plan on mounting the front camera to the location where you are going to mount the rear camera. This will give you a fairly reliable idea of how much you need. A little extra cable doesn't hurt as it gives you flexibility, but too much cable is a pain in the butt to deal with.