I wanted to build a good quality, ultra low distortion, stereo audio amp and after much searching, purchased the SC200 Audio Amplifier Module from Silicon Chip Magazine for AUD $187.28 Only one Power Supply needed though, so a little less. Only the hard to get parts are provided. I have used Mouser for the rest and Amazon for the heatsinks.
You have the option to use SMT or through hole. I went for through hole. There are a couple of SMT resistors that must be used but easy to solder.
2 Hard-to-get parts for the SC200 Audio Amplifier Module (Component)
2 New SC200 Audio Amplifier PCB [01108161] (PCB)
Ultra-LD Mk3/Mk4 Amplifier Power Supply PCB [01109111] (PCB)
http://www.siliconchip.com.au/ Not very cheap but excellent quality double side PCBs.
The support is excellent. Answer your questions almost the same day. Power supply is complete and works. I have nearly finished the first amp; just missing a couple of items.
I posted links to the magazine issues in the E-book section.