Hi Mr Skrunts,
I set up my own outfit last year and so far the investment is at £65k and I am nowhere near where I want to be.
Things you will need are:
Workshop - minimum of 1,500 square feet and approval to spray cars in there - this is not easy to get if it is not already being used as a spray shop.
You need an area to strip and fit, an area to repair and prep and a seperate area to paint.
3 phase compressor with dryer.
Spray guns, vacuum DA's, vacuum sanding blocks, vacuum masks
Pin puller, sliding hammer, welder (metal one and plastic one), shrinker, jacks, ramp
Mixing scheme - you can start off with a mimimix.
If you use less than 2 ton of paint a year then you can stay solvent, anymore you need to use water.
Spray booth - spray and bake ideally but you can use heat lamps.
Tressels and lots of them.
Gun wash cabinet.
Consumeables ie masking tape, masking paper, sheeting, sanding disks and strips, thinners, hardeners, gun wash, fillers, sealer, resins, glues, welding rods/wires (plastic and metal)
Fire proof cabinets to keep flammables in
Extraction systems - both dust and vapour
All manor of insurances.
Once you have all of that you need to make sure you can pull enough work in consistently to make it viable. When working with insurance companies be prepared to wait a minimum of 3 months to be paid for any work you do, I still have invoices outstanding from February.
PM me if you want to chat further mate.
Mark