An Apple IIe is fairly easy to repair, assuming the firmware has not been damaged. They used to sell kits for clones, such as the Pine-Apple, it was so widely copied that the clones are famous in their own right:
http://en.wikipedia.org/wiki/List_of_Apple_II_clones
IIRC the parts are all through hole, and many generic glue style chips.
One major snag in your resurrection attempt is did the PSU blow on its own or did is die because something on the mobo shorted? If it blew it suggests a filter cap went.
First, insure the PSU is actually working; you can simply tack on another PSU from a working PC to power the right lines; if it boots, the PSU is faulty and that's easy to replace.
Firmware I recall has a POST, and will help you decode what the fault is from there. I forget if it boots to BASIC or if it starts looking at drives to try and load DOS or ProDOS.
