Eagle also has a "Fisheasy 2" model out now, which is the next generation of this fish finder. The only place I've seen them advertised is Cabella's. I think they're about $30 more than the "Fisheasy 1".
I just use the suction cup on the stern. I put it on in the garage to line everything up and to make sure that it's parallel to the ground. I also found out that if you put it on when you have the boat in the water the suction cup seems to stay stuck better(make sure and tie the safety rope to something before you take off). I have the monitor next to the rower's seat. I sit on one of those one piece plastic lawn chairs with the long legs. Seems to work pretty well..