why not have a chat to the sales people in places like autobarn or supercheap just to get an idea of what oyu can do. Not sure where is best for buying though.

We purchased a Polaris Rearview Caravan system back in early 2006. http://www.polarisrearvision.com.au/ click on say the motorhome then the product tab at the top.

Seems they have a different camera (a dual one) for the back of the van nowadays. The previous camera (as per their CV-12 GPS system) is a bit too much of a fisheye such that you cannot really see distant vehicles.

The system works well for us, coupled with good side mirrors, giving a good clear view of what is approaching and behind the van.

Making up your own system from component parts is probaly cheaper, if you know what you are doing.

WOW!!  You really are out there. Sounds very interesting. Would love to see your set up, probably way out of my understanding but will ask a couple of whizz kids (like the grandsons!!) extremely reasonable cost.  May have to come back to you on this one.  Many thanks for your comment, talk soon.

We bought a 7" Monitor/Mirror  and 2 cameras off Ebay  two years ago.   Cost  less than $200 all up.     Came from Hong Kong.    
I fitted it all up myself in the Hiace,   works very well. 
  
Three weeks ago I  changed the cameras as they were a bit cheap (about$30 each)  not good  enough for use reversing at night.   Not a problem in daylight.
Just fitted a more expensive ($60 from China) reversing camera.  Works much better at night.   Has more night vision lights (cant think what they are called) like LED's only glow dull red !!!!!!

Because sometimes we had  the rear window obscured in the  Hiace  with gear,  I used one camera for "Rear View" and the other for "Reversing".  Since then we realised the Rearview for us was not needed.   Atered our stowing arragement. 

That Rear view picture anyway  was a bit distorted.  BIG Trucks looked like they were two kilometres behind you.   When in fact they were only 100 metres behind.  
 
Specify    "REARVIEW  CAMERA" or "REVERSING" when buying cameras.  

The monitor has two (AV1- AV2) channels so I could switch between  Rear View and Reversing views. 
It it the type that just clips over the existing rearview mirror.    When it is not switched on it's,  the rear view mirror.  
It has touch controls on the side to switch on and off.
Also changes channels. Plus Zoom, Brightness, Colour, Contrast.

I can use it in mirror mode, and also at the same time, have a little picture on one side of the mirror  of the  view behind the van.   
Which for us,  is the view of the rear step and area for about 2 metres radius behind the van. We have that camera on the top of the rear door looking down.

The camera picture view on screen is adjustable.
That is  the picture can be Full screen wide, Half screen, or Quarter screen.  

The picture position can be moved left or right on the monitor/mirror.  
So you can still have mirror view and also a camera view to see how close your rear end is to things,   at the same time.

I now have a user friendly auto elctrician.  Mobile setup so he comes  to you.  Specialises in Car Security and  Car Audio systems. but he will fit anything.   Think I would get him to fit up my next unit,   as he is five times faster than me, and worth the $$$$$$ for the good job he does.
On the other hand My next vehicle might have a GPS cum, reversing camera, fitted as standard.

Dream on Mike


Regards
Mike and Ellie