It doesn't need to be super securely anchored. I was running a 1U PSU in my micro cube w/ standard ATX PSU opening. I used 1 stock screw location. 1 jurry rigged bracket to the other side. and the overly long front end sat on top of the back end of the CD players.It was fine, and didn't flop when moving the case.
I was thinking about some sort of homemade bracket. I should also specify that the power supply I am trying to use if technically of the SFX Form factor. There's not really an official micro atx power supply in the intel specs. Also, I just realized I may have a problem with the wattage of the smaller supply. I'll have to look at it.
If you go the home made bracket route, sheet metal, plywood, or even thick cardboard coated in epoxy would all work. if you are using a junk case, a couple of zip ties through holes dilled in the back cover of the case.
In all honesty, just get get a small 80plus PSU. the cheap ones are generaly less than 70% efficient. My research was giving figures in the 65% area.
Assuming 100 watts power on average (a little higher than idle draw for new efficient systems)
100 watts = 876killowatt hours a year if my math is right.
1095 @ 80%
1348 @ 65%
or 253 kwh savings per year.
thats $25 @ $0.10 per kwh (less than national average) california is $.14, hawaii is $.32
so an efficient PSU will actualy pay for itself in less than 2 years, and your data will be safer.
I'd say; get an Antec case that includes an 80plus in 350/380/430watt PSU, as you are getting a new case anyway.
I recently purchase a cheap micro ATX case and a seperate PSU because the Antec cases dont have Kensington lock slots. It ended up being the same price as the Antec cases w/PSU. but "decent" cases don't come with kensington slots in them.
the PC P&C 370 is pretty cheap, and could probably run a mild gaming system.