Well after speaking with a couple of welders, I decided to give it a go myself.
I took my angle grinder to the boot and cut out the largest "non load bearing" section I could.
I purchased about $60 worth of angle iron, borrowed a $100 arc welder and went at it.
I've never touched a welder before, but i'm quite enjoying having a go.
Many of my welds look a bit messy ... but I can always get them redone once I have designed the boxes. Here is a photo of the rear battery box about half done.
I was really just practising with this rear battery rack because the most difficult job was making the new engine mounts and front battery rack.
After about a week of practise, I started working on the engine mounts.
Here is a photo of the motor in the car ... I have about 15mm play between the firewall chassis on top and the power steering rack below. You can see just above the motor, one of the two existing engine mounts I need to utilise.
As there is only one mounting bolt on the outside of the motor housing, my initial plan is to create a flat beam between the two engine mounts for the motor to rest on and then attach the beam to the mounting bolt and steel belt to stop rotation.
A weekends effort cane up with these ...
I don't know if it will be sufficient, but i will wait until i install these two before I create any more.