Looks impressive... Not sure you need all that expensive equipment but regardless... I would look at laptop screens.. They are generally setup for what you are looking for. And the best part about it is that you can try them out on a laptop to see how well they perform before trying to use them in your truck... Just get a replacement screen for that laptop and add a touch screen on top of it unless you find a laptop you like that already has a touch screen. I suspect this will be your best option and when the time comes for me to look at doing something similar for my 2003 Avalanche that is how I will likely go about it.
Another potential source is an all in one screen. Some of them are setup with touch as well.
And last but not least are industrial supply houses. Most places that normally use PLC's such as the ones in the back of your truck use a PC mounted inside of a case with a touch screen on the front. We have some larger screens where I work that are setup like that but they are not cheap. Looking at your truck I am thinking you don't care about cost unless you got those boards cheap used.
Not really sure why you chose a PLC setup like that. It is expensive, not designed for mobile use and the same job could be done with a handful of much smaller pc's and interface setups that are mobile friendly. You can expect connection issues that are hard to trace and I suspect component failure will be common place. Those setups are NOT motion friendly and don't handle changes in temperatures well. We have them here at work and they are very touchy. We have a couple of areas that are very humid and we end up changing out major components on a nearly annual basis due to failure. Again you would be better served with a different setup. I notice it looks like you have a rubber base to the unit but that won't resolve the issues. Good luck with that... I am doing something similar but I will be using an Intel processor in the console and multiple powerful ARM boards hidden in the interior. The only things that will indicate something different will be the screens and the cameras that will be visible. The Radar detectors are pretty hidden. There is a place that those PLC units work well but in a vehicle isn't one of them. If you are building a test system with the intent of downsizing later then I could possibly see it but it just doesn't make sense and isn't very practical as is.