jfint:

Take a look at this link: http://www.dotan.com/adjustment/#3 We supply rubber stoppers of different stiffness to suit different boat sizes.
Anytime you can lock the kick up mechanism by inserting a pin: http://www.dotan.com/adjustment/#4

As to prices, again it depends on the boat size, rudder blade(carbon / kevlar / fibreglass), final weight and other things.
Best way is to send us an email. Contact Info