Ready to purchase an Ultrex with ilink and MSI, Mega 360, and a helix MSI unit.

What cables other accesories would i need just to get these 3 going?

Not looking to link to my other units as they arent compatible, will upgrade those at a later date.

Been searching and cant find exactly what i need.

Check out this link -- find the option that best meets your needs.

Humminbird networking diagrams

iPilot LINK is an Ethernet connection, comes with a 30' Ethernet Extension cable. Need a AS EC QDE Ethernet Adapter to connect it to the Helix Ethernet port.

Both the MEGA 360 and Minnkota MSI transducer have a SOLIX 14-pin transducer plug. To connect both to the Helix transducer port, you need the 14 M360 2DDI Y cable--it is 10' long. It has two female 14-pin plugs for the two 14-pin transducer male plugs.
It has a 14-pin male SOLIX plug that has to be converted to 7-pin to connect to the Helix's transducer port.
You can use the included 10' 14-pin to 7-pin adapter cable or the Minnkota MKR-MI-1 adapter that is 3' long.
The adapter choice gives you 13' of cable to manage or 20' of cable to manage.

The MEGA 360 connects to the unit's SI circuits so it is impossible to use the SI piezos in the MSI transducer. The MEGA 360 does 360 and Side Imaging but not at the same time. You will get DI/2D/Temp from the MSI transducer.

Thanks for the info guys!