I'm leaning towards a mechanical system instead of hydraulic. The Bay Star system by Teleflex, around $500, is on the low end of price. Teleflex's Sea Star and competitors brands, such as Don mentioned, the Uflex Silversteer Hydraulic O/B Steering System, are $800 and more and are built rugged. Hydraulic systems are discussed on Scream and Fly's forums. Even these higher end systems have problems with seals, adjustments to take out play, etc. I will do more digging, but I'm leaning towards the tried and true mechanical such as the Teleflex NFB single rack steering system.