iTouch based enclosure for polytune app

[MediaMan09]

I have all the pieces, and everything works, just looking for some ideas on putting it all together. I'd like to have an enclosure where I can keep my itouch, for use with the polytune app. See concept below. First two questions:

1) what options are out there re ipod docking hardware?
2) is the microphone only acceptable via the TRSS jack, or is it also available via the docking connector?
As a mimimum, was thinking of the following:
- enclusure: wide enclosure such as the Hammond 1595
- Itouch : on the top of the enclosure - slides into a case or fastened with velco
- Microphone - lapel mic sitting on top of enclosure (wiired to the TRRS cable inside).... or....used an input jack at the back
- Audio out :  output jacks  or cable the rear of the enclisure , connected to the TRRS cable inside
- USB - connector or cable out the back

[MediaMan09]

Follow up:

To make use of the tuner function on apps like polytune and guitar toolkit, I use a 4 pin TRRS AUDIO-VIDEO cable such as this :

I connect a microphone to the video connector (as weird as that sounds)  and it works like charm.

My quesiton is this:
Something like the idock, would be perfect for this diy project, as I can avoid any loose cables, and just dock the itouch. The idock uses the same type of cable, eg

(Also see here:  http://www.youtube.com/watch?v=yTLR5q2Wr_M&feature=related

But at the dock end, would the microphone still work off the video cable??

[I3enjam1n]

Follow up:

To make use of the tuner function on apps like polytune and guitar toolkit, I use a 4 pin TRRS AUDIO-VIDEO cable such as this :

I connect a microphone to the video connector (as weird as that sounds)  and it works like charm.

My quesiton is this:
Something like the idock, would be perfect for this diy project, as I can avoid any loose cables, and just dock the itouch. The idock uses the same type of cable, eg

(Also see here:  http://www.youtube.com/watch?v=yTLR5q2Wr_M&feature=related

But at the dock end, would the microphone still work off the video cable??

i think it won't work, because ipod dock port have it's own video out pins. But there is also pins for stereo line-in and stereo line-out, as you can see on this site: http://pinouts.ru/PortableDevices/ipod_pinout.shtml
Check also: http://www.head-fi.org/forum/thread/500149/itouch-3rd-gen-line-out-dock/15