Very cheap and easy to do.

Main chassis.

Bumpers, suspension bits, body posts, etc

Mid wheelbase adaptor

Each of these parts is about $5 from Banzai Hobby. They ship fast and super cheap, too. The first item is the entire chassis. The second item will supply you with the bumpers, front body posts, servo mounts and front upper arms. The third has the mwb adapters, but you can buy alloy ones from 3Racing and others.

The only other things I can think of that you need would be a servo saver horn with two holes in it, like a Kimbrough large and a couple of 23-25mm turnbuckles for the steering linkage. Have a look through the manual and you'll get the idea.

Here's the instruction manual. Have fun!