Check out this post on the Surf Photographers United forum from Philippe Chevodian of Liquid Eye housings which highlights their latest budget housing design, it features a permanently attached pistol grip and the standard removable front plate.
The big story though is the price of the housing: US $795, (about £520) so even with shipping to the UK and any other extras I imagine it’s the cheapest option for someone looking for a decent lightweight housing for their DSLR.
They also list quite a few different types of cameras that will fit:
The C1600 can fit many small DSLR’s such as the Nikon D300, Canon 40D, 50D, 7D, 550D 5D, etc.
This multi camera compatibility seems like a sensible idea, I imagine you order one for your specific camera and any adjustments (connector for the pistol grip for instance) are made to the basic shell before sending it out.
You will obviously be missing out on controls for the camera, not ideal, and I’d probably want to get a dome port too, and the two stage pistol grip will be pretty much essential if you’re not shooting fisheye, so the price will ramp up a bit, but it’s still a fraction of the price of a new housing from someone like Aquatech or SPL.