Highly recommend this place:
https://goo.gl/maps/acWAGrRQV8mKqxQS8
They know their stuff when it comes to installs.
Also one of the few shops that doesn't mind at all if you buy your electronics online and just bring them in to do the install work. Prices are very reasonable for install work also, IMO. (if you have any experience doing your own installs you will understand what a hassle and how time consuming it is to do yourself).
If you want to go this route, spend some time today shopping Amazon, and another favorite of mine Sonic Electronix, to find what you need hardware wise. Crutchfield has a good website also but their prices sometimes are not as competitive as the others.
Make sure you do your homework before purchasing, and buy something that is compatible with your vehicle. I've seen the mirror monitor systems, and at least for me, the screen was so dang small it made it hard to see - although still better than nothing. Maybe you can find a Ford forum and find out if you can simply get a camera and wire it into any view screen already on the vehicle? (not even sure if your van has one - just spitballing).