Are you Ian in the same area of Norway as Ole (vforce)? He's using a nifty electric screw drive from Carson (I can't find the product listing on Carson's site) that gives a smooth realistic lift speed from bottom to top & back again. It's quite powerful too.
There really is no comparison for scale hydraulics for dumpers and Scale Art makes a nice telescope hyd system. I haven't tried one myself yet, but maybe someday.
http://www.scaleart.com/produkte/bauteile/hydraulik.htm
The Wedico telescope has been working good me, use one in each of three trks.