[Qman]

The other alternative would be a 3D printed chassis. Amato Slot Car Design and J May who are in the traders section of the forum both produce adjustable chassis. If you can't work out what you need from their product list just drop them a message with the dimensions of the body and I am sure either of them will be happy to give advice on the best match for your body.

John May has been known to print a chassis to your dimensions if spoken to nicely, I have one produced by him for my Trabant.