Used a £10 bracket from Index catalogue and made a few modifications (cut away some metal where the air intake is on the side). Its purpose would normally be for hanging a video under a cabinet so its plenty strong enough for my AE100 and clamps the projector tightly...then used a few L-shaped brackets and screwed straight into the ceiling joist.
I have to say, from my experience, you are just as well to make a bracket. I thought it would be too much hassle, but I did it and it was easy and cost next to nothing.
Measure the surface area of the PJ.
Measure how far down from the ceiling your PJ will need to be (hold it up there whilst it is on and get someone with a tape to measure)
Go to B&Q or a timber merchant. Get one piece of mdf cut to the size of the PJ, and another cut similar, or a bit bigger (square as opposed to rectangular if you like). Go for quite thin stuff, it does not have to hold much weight.
Then, get a piece of "finished" (i.e. smooth) 2"x2" cut to the length of drop you need, less the thickness of the MDF x 2. Wilst you are there, get another couple of pieces cut, one a bit longer and one a bit shorter to cover your bets.
At a timber merchant this little lot cost me £6. Grab some white gloss whilst you are there (a tiny tin will do). Oh, and grab four 4mm bolts that will be long enough to go through the mdf and into the PJ with a couple of CM to spare. and make sure you get 8 nuts( 4 washers are nice to have too)
Go home, using a paper template, mark out the four 4mm holes on the PJ and drill holes for the bolts in the rectangular MDF. You may also want to cust a bit of the mdf away to allow removal of the air filter.
Test mount the PJ to the mdf with the four bolts and eight nuts (one nut above, one below the mdf). When you are happy, fix the 2"x2" wood to each piece of mdf centraly, like a bird table, with one very long wood screw at each end.
Mount the PJ, test your positioning then all you have to do is whack another 2 long wood screws through the top mdf into the ceiling, finding a wooden joist. I found a joist by working out where the mdf needed to go, then drilling a few tiny pilot holes until I found one. Believe me, 2 long wood screws is plenty. I have hung from the bracket with no movement .
Because of the screws and nuts you can now adjust the height and level of your PJ easily.
DO REMEMBER that the Lens is not in the centre of the PJ - I made this mistake and had to move the bracket :-(
Once painted white gloss it looks fine. I thought it would be a real eye sore, but it blends into the ceiling really well and looks quite professional.
And, because you have used only one screw to fix the lower mdf to the 2"x2" post, screwed "Quite" tightly, you can rotate the PJ for fine adjustments.
I'll pop up a piccy later.
If you search these forums for "mdf" and "PTAE" etc you will find a chap who has done a real nice one like this with pictures. (I copied his!).
It is good fun to do, and you really don't need to be a handyman, and you don't end up with a big ugly metal bracket.
Hey, that Gyrolock looks very nice, the white makes all the difference. Might have to get one next time....
Anyhow, some pictures of a quickly and cheaply knocked up solution as described above. You can see my ceiling is high - shame I've not got round to removing the god aweful Anaglypto.
My only regret is the cable trunking, but to be honest, in the scale of things is you don't really notice it (the room is large and split in two by the beam you can see, which obscures it mainly) and I really could not be arsed to lift the floorboards upstairs!