Hello.. not sure if you cut these yourselves or if you get someone outside to do them for you and then bend/sell-on.. if you have the capacity to cut these yourself in-house, then it might be worth looking at the BMW strengthening panels on the market, in particular E46 rear subframe reinforcement plates (which are bent/laser cut and fairly thin plate), E36 trailing arm pockets (thick flat plate), E36/46 front subframe reinforcement plates, E36/46 rear anti roll bar bracket reinforcement plates, E36/46 transmission mounting reinforcement plates, E36/46 rear damper reinforcement plates in both normal and off-set versions (all simple flat cut plates except the rear arb bracket plates which have one bend)
These all sell for a reasonable amount, but there's not many people in UK / Europe selling them - they're mostly imported from the US and sold on.. Might be a nice side-business for you if you can nest them around other things you're cutting out
Ben
PS.. There are also rear subframe reinforcements for e36 but these are thick stamped plates and they're only a few quid from the dealers, gearbox mounting plate reinforcements are available too (but not everyone knows about them), and front strut top-mount reinforcement plates, which are pressed - these are all probably too much of a pain in the butt to worry about
