On my phone, so limited resources on hand.
CES distributing for dang near any part.
London Power in Canada for extremely in depth books and kits.
I've got bunches of links when I get home.
-C
Okay, here are some links:
https://www.cedist.com
http://www.londonpower.com
and this guy, but he can be hard to get responses from:
http://torresengineering.stores.yahoo.net
This is a great book, with a kit all spelled out (you can get all the parts at CE)
http://www.amazon.com/Guitar-Amplifier-Handbook-Understanding-Amplifiers/dp/087930863X
and this place for tons of talk:
http://www.vintageamps.com/plexiboard/index.php