I have a Baystar Hydraulic Steering system for sale. This is rated for up to £150hp either as a single or twins. You can see all the info here- BayStar Outboard « Teleflex Marine
Its BRAND NEW all in the original packaging and includes the pipes (20ft pipes), connectors, instructions, fluid and the hydraulic ram with the Mercury/Mariner/Tohatsu connector.
It's minus the "helm unit" (Part number HH4314) which is available separately on Ebay for around £150.
So grab yourself a bargain and get rid of your troublesome cable system!
You can collect it in person from Hemel Hempstead or I'll post it to you at cost. Bottom line is I'm looking for around the £200 mark.
PM me for more info/pictures etc.