The icom ic-7100 is a fantastic little radio, specially when you have limited “shack” space. I’ve decided to fix it on my desk using a ram mount I had on hand for a old gps I don’t use anymore.
The kit used is ram mount :
RAM-B-138U (dual mounts and short arm)
RAM-B-201U-C (a long arm to replace the short arm)
You can also simply order parts by parts what you need. My setup use the 1″ ram balls and the radio screw directly under the RAM-B-202.