It's a straight forward install. Removing the Manual steering cable can be a PITA. With the fact that your going to replace it, cutting the cable close to where it enters the tilttube on the motor [2in or 3in] away. This will make things much easier, as you don't have to pull that stiff end back thru the rigging tube.
Some motors have to be unbolted in order to get the cable out and flexed around enough to get it thru the rigging tube....Some boats you don't.
Cutting the cable will save you several hours of work.
Brand of hyd. steering......While Teleflex has been the most popular and you will find a lot of it out there. I've switched to U-flex...Got tired of Teleflex leaking.
Get the Full size system....Not the baby version designed for 150HP or less.
You mentioned Autopilot..... Get Ready.....That stuff is EXPENSIVE!