Midi Switcher - Ready to build?

[jimosity]

Does anyone know of any ready-to-build midi switching units?
I've tried reading and searching and my brain just can't wrap around all of the info; it's just too much.
I just want to do 1/4" jack switching via midi; like an Axess Electronics AC8; so I can switch channels.
I need half to be momentary and half to be latching.
It doesn't need to pass audio thru.

I've looked at the "project crossbar" and read most of the other sites before my brain turned to jam and was hoping that someone may be able to point me to a specific project that already addresses these needs.

[Processaurus]

Don't know about an abolutely nailed down project, there are a couple commercial switchers out.  This place that's been intriguing me sells the crucial building block, the midi decoder, as a kit:
http://highlyliquid.com/kits/decoder.html

[jimosity]

Yeah; that's come up a few times in searches; specifically the MSA-T
I'm just not 100% sure on what else I would need to build it out.
Relays and jacks are obvious, but I'm not sure what else.