Hi Andrew. I posted the three ways I've seen for an antenna with no backstay on your previous thread. For the group, the three ways I have seen a SSB antenna is:
1. a whip off the transom.
2. a fake "backstay" that was used as an antenna.
3. the last was the most interesting. There was a 410 that cut up sections of his upper shrouds, isolated the sections from the rigging, and then connected the sections with wire together to form his antenna.
Maybe someone in the group has another idea.
The ICOM M802 is a great radio, and is very easy to install. I was able to do everything myself in about 8 or 9 hours of work. Having a separate control head makes mounting the unit a snap. There is about a quarter amp drain at all times, even when the radio is off (used to keep the frequency more stable upon startup, important for e-mail only). To get around that, I ran the power through a circut breaker on my DC panel. I took the easy route and ran copper foil to a thru-hull in stead of installing a dynaplate or running copper everywhere. Works great. And use RG213 if you can for your coax from transceiver to the tuner.
A couple of tips as well:
You will need a separate DSC antenna. Gordon West suggested taking a 15-20 foot section of any good coax and running inside the wire runs just below the deck. Works fine, we found out one night when someone pushed the button on their SSB radio. I bought a premade 25' RG58 coax and ran it just below the deck joints behind the bulkhead.
Dockside Radio sells a pre-made data cable for the DSC function. It was cheaper then buying the parts to make it up myself. You can look him up on the web, Gary is a great guy and helped me out a lot.
Hope you are also getting your ham general license as the radio does both very well. And just send me a message if you have any questions. I also have a couple of pictures of my nav station on my profile page.