Well, i may be a bit clumsy around windoze and *nix, but i do have some more knowdlege on electronics:
You said the power supply was on fire, right> Take it out of the case, and check the wiring inside, and the fuse. As far as the wattage it can supply, the more the better, so that's not the problem. Also check all your system cards for burn marks. Do you ussually get voltage spikes at home? you may want to get an UPS or at least a regulator to prevent those. If you find out that the power supply was the problem, you can replace it without needing to get a new case.
Also, check the voltage on the ram... have you been trying to use 3.4V ram with the system set to 3.3V (or vice-versa)? Shouldn't make your power supply light on fire tho. I still think that it's all pecause of a voltage spike.
