"Are you looking for "mech
"Are you looking for "mechanical" steering or "hydraulic" steering.
Teleflex sells a few mechanical "steering in a box" set-up's, rotary or rack style helm with single or double steering cables and even a steering wheel, starting around the 200 buck mark.
If you want hydraulic, you could go with Teleflex's "BayStar" system which lists for close to 800 bucks but can be picked up for under 5 bills at most discount marine places.
If you go to the Teleflex website, the have instructions as to how to measure your particular rig to determine what "cable length" you need..."