ShilohRed,

The transducer that comes standard in the box will do both ( Side Imaging & High Speed) The only thing is on a typical bass box you are running 70 mph and the transducer is large in which it has to be of side imaging, the transducer will act like a ski. We recommend that you install the side imaging transducer right under the jack plate so when you are running the side imaging transducer is out of the water and then epoxy a transducer in the hull for 2D high speed readings. Then the Y cable will attach the two transducers together and then connect to the unit. By doing this you do not have to have a switch to swicth back and forth. The Y cable does everything for you. Using the Y cable is easy press the view key from 2D to side imaging. Using the transducer switch you have to remember to switch from 2D to side imaging.

To answer your question you can use the transducer in the box for high speed reading and side imaging.

I would suggest the 787 C2 for the unit on the bow and a 997 on the console.

When using interlink you can use 2 gps receiver at a time. The unit will default to the interlink. You can go into the unit and tell it to use the external GPS receiver. You will have a Y cable that comes in the box that will allow this setup.