Hi Russ,
I think that you should reconsider the need to install a bow thruster. I have a 2005 270CR and I also have a USCG 100 Ton Masters License. I operate single screw, twin screw and jet drive boats. With 30 to 50 dockings a day (more than most boaters do all season) I have yet to find the need for a bow thruster. With the right plan, preparation and practice you should be able to dock your boat, single handed and look like a pro. I would suggest a few lessons from a competent captain (much cheaper than a bow thruster) and practice, practice, practice! (Preferably on a well fendered dock)
Good luck and happy boating,
Jeff