Can I have a rear view one for the back?
YesIs a rear view camera the same as a reversing camera
Yes, but do you want to just view or record?Can I have the wires going under my van to the connection at the front
So many options/things to think about here
Is it going to be mounted top or bottom of van? if top then best feeding wires into van rather than having them on show outside, if mounted at bottom then easy enough to feed under van.
You will need 2 cables, power and AV
If you only want to view when reversing then you could get a wireless system, only power needed for the camera then is a +ve and -ve which could be taken from the reverse light feed so it only comes on when put in reverse, the monitor will have its own power feed in the cab.
If you only want to record for accident purposes then just fit a dash cam - but don't put it on the dash!!!