I recently purchased a PC-07SX case, and have a suggestion on the design that might be helpful.

The bracket that mounts the PSU into the case does not allow proper mounting of Thermaltake tough power PSUs (at least the 750w model I have), because the cord socket has a guard around it that sticks up about 1/4". The guard causes the left edge of the PSU mounting bracket to be pushed up so the PSU will not mount flush. If you shaved about 1/16-1/8" off the inside edge of the bracket it would fit perfectly.

I posted a couple of images for reference:

Imgur: The magic of the Internet

this may be an issue for other PSUs as well, but I haven't tried a different brand yet.

To that end, can you suggest which PSUs are known to fit properly?