This is not a question about which sounds better, I've owned a Hamptone and I've owned API modules. I've just never assembled my own pre. Both are great sounding pres and I wouldn't assume the SC A12 to sound any less stellar.
I purchased a practice board from Radio shack with some resistors and did really well. I've soldered my own cables many times in the past. So it's not really about soldering, as I can do that pretty well. It is more about *organizing* and *assembling* all the components in the right order and the correct direction.
Which assembly would be easiest, the Hamp or the A12?