Hi!
Here is a FET amplifier that appeared in a DIY magazine. Its work perfect, the first and second stage are stabilized and the sound is very good. I know to advise.
Isaw your amplifier pictures and I think the long wires with MOSTFETS is bad idea. Mosfets has big input capacity and your amplifier will maybe to generate.I think would be better if you would to build the FETS on the PCB.The DIY magazine also built directly on the PCB the FETS.
Good Luck!