The frame for the chassis is going to be built from 16mm stainless steel tube. At present, it is simply a rectangle with inner dimensions of 300mmx400mm, but we will definitely extend it into a trapezoidal shape, and we can add reinforcing beams if necessary.
I stumbled upon this site while I was looking for metalworking circular saw blades. It has some good tips and info.
Check the comments for progress updates.