Directly from the DIY links post
CHASSIS , ENCLOSURES , FABRICATION , PROTOTYPING
Hammond Enclosures: Very large selection
http://www.hammondmanufacturing.com/scpg.htm
Design,build,Listen-off the shelf and custom work
http://www.designbuildlisten.com/
Active Plastics
http://www.activeplastics.com/
On-Line Metals
http://www.onlinemetals.com/
http://www.thlaudio.com/
Front Panels Made to Order
http://www.frontpanelexpress.com/
PacTec Enclosures
http://www.pactecenclosures.com/
Beautiful Wood! Perfect for that Tube Amp.
http://www.welbornelabs.com/woodchassis.htm
Yeager Audio-A really nice chassis at a fair price that is perfectly sized for a stereo tube amplifier.Is finished in s oft gloss black,c\Comes with the IEC jack,Fuse holder and rubber feet so all that is left is the actual tube socket hole cutouts.
http://www.yaegeraudio.com/
LMB/Heeger
http://www.lmbheeger.com/
BUD Industries
http://www.budind.com/index.php3
SESCOM - good selection , custom chassis punching available
http://www.sescom.com/enclosures/enclose.html
Lansing Enclosures
http://www.lansing-enclosures.com/
PAR metal
http://www.par-metal.com/
AudioKits-small but nice selection of audio specific chassis/enclosures at a fair price
http://www.audiokits.com/products.asp?catid=111
IAG (International Audio Group) : These are very nice aluminum chassis with hardwood caps.Not cheap but very nice just the same.
http://iagaudio.com/products.asp?id=4
Enclosures And Cases Dot com :Nice selection of quality chassis-cast tube,rack style,desktop,flanged
http://www.enclosuresandcases.com/index.html
AmpboxAudio : So far only two offering but those two are really nice.One is a drop in for the Tripath amp,the other is a "Eurobox" and accepts standard Euro-cards-
http://mywebpages.comcast.net/ampbox/index.html
Germany
Fischer Elektronik
http://www.fischerelektronik.de/
Zero Cases : Unusual but very nice deep drawn metal enclosures (custom work available)-
http://catalog.zerocases.com/
OTHER HARDWARE
BrownDog Adapters: IC adapter boards
http://cimarrontechnology.com/index.asp
Just a really nice knob
http://www.welbornelabs.com/hardware.htm
The knob is no longer listed on the website !.Will update link if it re-appears.
Wood Knobs
http://pages.sbcglobal.net/quackfat/_wsn/page5.html
DIY Wood Knobs
http://www.audiotweaks.com/diy2/scott_knobs/page01.htm
Anyway, you could aways make your own.. metal supermarkets is cheap and quick, and you could always ask your local community college to let you use their shop.. you could get a very industrial and nice, albeit heavy, case in about a hour and cost you little. meh. I'll stop talking.. I suggest par-metals =p