I got a steel galvanised drivers door from SP. I'm happy with it apart from one thing. The tubes through the door where the hinge bolts go through were way too long. They protruded about 3 mm. I could just get the nuts on with a couple of threads and not enough to engage with the nyloc. Fitting one of those anti-theft plates was impossible. After grinding the extra tube flush it still wasn't quite enough to fit the anti-theft plates and engage the nuts fully. I ended up using the door bolts used on the rear doors which are notably longer, and cut them down.
Anyway, apart from that hassle, the door is ok and I'm happy with it.