Hello there,
You don't need any electronics expertise to put together a Crack.
The toughest part will be completing your first solder joints, but if you look at what things look like in the manual and do your best to imitate, then you won't end up with any troubles. (When repairing kits that get sent in for the flat rate repair, I see many cases of way too much solder, so watch for that)
The one thing worth mentioning is that the listening experience of Audeze headphones are low sensitivity and low impedance, and the Crack will not drive them all that well. The SEX amp, on the other hand, will work marvelously with them.
If you're insistent on a Crack, then you can pick up a used pair of HD-580's pretty reasonably, then see if you like the high impedance headphone and OTL amp combo.
-PB