There is an Icom IC-735 Yahoo Group.http://groups.yahoo.com/group/IC-735/
1: Any recommendations for the rig to computer interface (not the ICOM unit as they are really hard to find).
Icom uses the CI-V interface (2-wire serial network "bus" developed by Icom in early 1980s).
DF4OR: Icom CI-V Informationhttp://www.plicht.de/ekki/civ/
To connect the Icom CI-V bus line to a computer (RS-232) you need a LEVEL CONVERTER,
which converts the +/-12V of the RS-232 interface to 0V/+5V of the open collector bus line.
ICOM offers such a device, called the CT-17 (which you referenced).For UNIVERSAL SERIAL BUS (USB), Level Converters are available from:
Silicon Labs and FTDI. FTDI has BEST support for OS (Windows, Linux, OS/X, iOS, AndroidOS, etc.) Driver support.
There are several designs to build your own (DIY) converter,
the schematics are all fairly simple (and cheaper).
Here is a listing of various RS-232 and USB approaches:http://www.plicht.de/ekki/civ/civ-p2.html