can you recommend a remote wireless system? Or two?
RayMarine, Garmin and Navico all make wireless remotes. Panther T4, PowerTran, and Troll Master all make remotes for kicker tiller steering.
I have taken auto pilots which do not have remotes, and set up a wired remote which just activates the solenoids on any autopilot pump motor. Red button to port, green button to starboard.
TrollMaster makes a good kicker throttle control. There are others, but I suggest the TrollMaster because of the relatively low price and long history of manufacturing the units.
If you have steering already in the cockpit you can put a link from the closest 90 Hp to the trolling motor, and use the wheel, or the boat's autopilot to "rudder" plus the actual thrust of the trolling motor for steering. Putting in remotes for the 90 hp outboards gets a bit more expensive--Either double on the throttle and shifter, or go to wireless shift and throttle at the helm and cockpit from either the engine manufacturer, MicroCommander or ZF Mathers. Sticker shock $$$$ for one of these! Some have gone with them.
If you really want sticker shock--one of the engine manufactures joystick docking systems stem, with twins, which pushes the boat sideways, by independently steering and shifting each engine. $$$$$$$ Optimus 360 Dometic (was Sea Star/Teleflex) $$$$$$$