Stick with FLdigi, you will be better off.
Now I donot use a MAC, I run Windows here with the Icom 706MKIIg, IC-703 and the IC-718.
I highly recommend using the 6pin Data Port (Packet). Using this Jack you don't need to either turn off the Mic Gain or Disconnect the Microphone itself.
If you use the 13pin DataPort then you will have to.
Its been awhile since I used my 706MKIIg but I do run Digital on the 703 and 718.
Fldigi runs very nicely with these radios. When it comes to CAT control for the 706MKIIg the CI-V commands are very limited.
In fact my 703 has more CI-V commands than the 706MKIIg or 718.
I run 3 Tigertronics Signalink USB Interfaces plus the CI-V cables with FLdigi and all works very well.
I dont know much about CocoModem but I believe it can not hold up to FLdigi.
If you decide get into Emcomm then FLdigi is the best out there for that.
If you don't already know their is a Yahoo User Group for those who run the Apple and Linux Operating Systems at:http://groups.yahoo.com/group/linuxham
(Main FLdigi Group)
73 de Steve KB6HOH firstname.lastname@example.org