Have tested the Rack and Pinion suspension and it can carry up to about a 10kg load max, that gives me an all up waight max of 120kg which really should not be an issue but i would perfer to have a bit more head room so i found some off the shelf springs that are slightly larger wire size, the down side was that they are twice as long as what was needed, so in the cutter they go and 30 sec's later i have two springs for the price of one :)
I installed this into the prototype and these ones take up to 14kg no issue so that gives me an all up load of 168kg max, this is working on only the back 12 road wheels being load bearing.
I have redisgned the prototype and will hopefully be able to cut a set out today so will post pics once i have them.

I have also been busy working on the road wheels and have found some plastic pipe the perfect size for the wheels and getting some steel tube cut to length as well for the hubs.

Still waiting on the new side panels to come back from teh folder but hopefully they should be in early next week.