I have a Minnkota terrova with the Ipilot Link system tied into a Humminbird Helix 10SI. Love the set up for sure. As far as hooking everything together if you just use one fish finder and the electric with the Link system you don't need the 5 port ethernet hub but as soon as you add one more fish finder for the bow you do. For $1000 fish finders I would either suggest a helix 9SI or the Helix 10 sonar/gps combo. The SI will have sonar, GPS, down imaging and side imaging where the other one would just have sonar and gps. I don't know if you are wanting any kind of imaging in your new units. Also if you get one SI unit and hook them together using the ethernet hub you can pull the SI images to the non SI unit so that will save you some money. A couple other things to note on the helix's. The helix 9 and the helix 10 are in the same size plastic housing the 9 just has a smaller screen in it. Also the helix 9 SI comes with the non HD transducer while the helix 10 SI comes with the upgraded HD transducer. These are both fairly heavy graphs that weigh somewhere in the neighborhood of 4-5 pounds so I would suggest a better mount that the RAM. The RAM will work but after a while especially if you are in waves it will move no matter how tight you get that clamped down. I have mine on a Cisco Sure-lock mount and there is no way that it is moving. They are a little more than the RAM but well worth the money in my opinion. Another thing to mention is that you will not be able to share maps over ethernet between your bow mount and dash mounted fish finders. The waypoints and tracks will transfer over but not the actual maps them self. In order to get the maps on both you have to buy two copies of it so that each unit has the SD card in it. Both the Helix 9 and 10 come with autochart live built into them so that you can create your own maps as you drive around which is awesome but that is a whole other conversation in itself.
The ultera is a great motor and I think that you would like it. I opted out of it just because I have a RAM trolling motor stabilizer on my motor that wouldn't allow it to auto deploy which is really the only difference between the ultera and the terrova. That saved me a few hundred bucks right there.
I have a fair amount of knowledge on these motors and fish finders and how they interact with each other so if you have any specific questions just let me know.
Ryan
