FWIW, the FTM-350 is handy because it has a mic port on the face and the body, you can use either although it's probably not a good idea to use both simultaneously. You can extend the jack using standard Ethernet cabling and a female-to-female coupler.
I hang my mic in an empty slot on the dash using one of Nakman's nifty dealies, with an Ethernet cable running from the body of the radio under the seat up to the console and the mic plugs in the middle with the cable headed down instead of up to the face. Some people have made a little bulkhead for the coupler so that the mic plugs into the dash like it's a factory option, although I have not gone to that length yet. Maybe on the new truck I will do that. Although I'm waiting to see what the FTM-400 looks like and costs, since the FTM-350 is discontinued.
I have the face mounted above my rearview mirror as well, with the control cable routed down the A pillar and under the door sill.
CHiRP works on the FTM-350 very well and I have converted pretty completely over to it for all my radios. It makes copying and pasting memories even between brands very easy, no conversion to CSV or anything. I still use the RT Systems cables, since I had most of them anyway. This set up also lets me use Mac OS X instead of Windoze. RT uses FTDI USB chips and editing the kext file to support all the cables is super simple.