Hopefully someone finds this useful! As of this posting, I have not actually ordered these parts, so I’m not 100% sure of the reliability of these companies or parts, but I’ll update this post later if I find any of these parts don’t work.
First of all, everything I could from SmashTV ( http://www.avishowtech.com/mbhp/buy.html ), I did.
48x ALPS tactile switches
http://www.mouser.com/ProductDetail/ALPS/SKHHDTA010/?qs=sGAEpiMZZMsqIr59i2oRcqShR6iETrbseFQPH8gstG4%3d
4×20 character LCD display
http://www.crystalfontz.com/products/2004a/index.html
15x Rotary Encoders
http://www.mouser.com/ProductDetail/Alpha-Taiwan/RE160F-40E3-20A-24P/?qs=yA6kp8fx8Y7zlmuFqx9z8g%3d%3d
50x 1N4148 small signal diodes
http://www.mouser.com/Search/ProductDetail.aspx?R=1N4148_T50Avirtualkey51210000virtualkey512-1N4148T50A
Fan
http://www.performance-pcs.com/catalog/index.php?main_page=index&cPath=36_123
http://www.performance-pcs.com/catalog/index.php?main_page=index&cPath=36_91_110
Hope this helps someone!
I *really* need to post my parts list and update the wiki. I’ve been meaning to do this for ages. All of these parts were used with success in my MB-6582. Here’s a partial list of what I used:
Fan - 664-AD0405DB-G70-LF - Just a normal fan (no backlight).
http://www.mouser.com/Search/ProductDetail.aspx?R=AD0405DB-G70-LFvirtualkey66400000virtualkey664-AD0405DB-G70-LF
Fan guard - 562-08149 - Chromed
http://www.mouser.com/Search/ProductDetail.aspx?R=08149virtualkey56210000virtualkey562-08149
10mm threaded spacers - 855-R30-1001002
http://www.mouser.com/Search/ProductDetail.aspx?R=R30-1001002virtualkey57420000virtualkey855-R30-1001002
Diodes - 512-1N4148T50A
http://www.mouser.com/Search/ProductDetail.aspx?R=1N4148_T50Avirtualkey51210000virtualkey512-1N4148T50A
Encoders - 318-ENC160F-24P
http://www.mouser.com/Search/ProductDetail.aspx?R=RE160F-40E3-20A-24Pvirtualkey14860000virtualkey318-ENC160F-24P
Tactile Switches - 688-SKHHDT
http://www.mouser.com/Search/ProductDetail.aspx?R=SKHHDTA010virtualkey68800000virtualkey688-SKHHDT
DB-25 connector - 571-5-747913-2
http://www.mouser.com/Search/ProductDetail.aspx?R=5-747913-2virtualkey57100000virtualkey571-5-747913-2
DB-25 mounting kit - 571-5207719-1 - You can use bolts you already have instead of this, but it’s nice to just have the exact right parts.
http://www.mouser.com/Search/ProductDetail.aspx?R=5207719-1virtualkey57100000virtualkey571-5207719-1
Feedback pots - 313-1250F-100K - 100k linear taper. You can use other values also. I also tried 500k audio taper but preferred these. You might try other values. These have a .25" shaft for knobs.
http://www.mouser.com/Search/ProductDetail.aspx?R=RV122F-20-15F-B100Kvirtualkey14860000virtualkey313-1250F-100K
Knobs for feedback pots - 450-2050-GRX These have a yellow top so you may want different knobs to match your color scheme.
http://www.mouser.com/Search/ProductDetail.aspx?R=450-2050-GRXvirtualkey56100000virtualkey450-2050-GRX
Stereo mix jack - 161-7300-EX
http://www.mouser.com/Search/ProductDetail.aspx?R=161-7300-EXvirtualkey11180000virtualkey161-7300-EX
40-pin right-angle headers - 517-5111TG - If you want to use headers on your control surface board instead of soldering wires directly between the CS and base PCBs, these worked well for me (see my pics, link below).
http://www.mouser.com/Search/ProductDetail.aspx?R=2340-5111TGvirtualkey51750000virtualkey517-5111TG
3mm LEDs - 604-WP7104SYD - These are yellow, but use whatever you like. Don’t forget to get one for the rear panel power indicator!
http://www.mouser.com/Search/ProductDetail.aspx?R=WP7104SYDvirtualkey60400000virtualkey604-WP7104SYD
20x4 LCD - CFAH2004A-YTI-JT - Yellow-on-black, but use whatever you like. This is a relatively expensive display but I love the way it looks.
https://www.crystalfontz.com/product/CFAH2004AYTIJT.html
Be careful with this list. Some of these are yellow which may not work with your color scheme, but hopefully they will be a useful reference. Also, with these LEDs I had to use larger resistors to get the brightness down to a good level. I don’t have the # in front of me, but I can check after work and see what value I ended up using for this. I ended up using 2.2K resistors. Note these resistors are changed on the base PCB, not the control PCB. But you may prefer your LEDs to be brighter than me. 
Here’s some pics of my MIDIbox so you can see some of the parts I used: http://picasaweb.google.com/fussylizard/MB6582?authkey=Gv1sRgCM7npqbPgvbfYA&feat=directlink
I’ll try to put together a list of the other parts I used also since I also used a bunch of bolts and stuff plus a few other things (mostly headers/crimp pins) from SmashTV’s shop. But now I’d better get working. 
Good luck!