Dave - this probably down to personal choice and budget. I looked at this option last year for my hard floored SIB, then decided to save the cash and save it towards a RIB.
It will not be cheap - I looked at a system from International Marine Supplies http://www.internationalmarinesupplies.co.uk
Tel: +44 (0)1427 617845 - but don't forget to add up the cost of all the components - (cable) steering kit, wheel and mount pedestal/console, and the throttle/gear remotes, along with any electrical work (are you man or elec start?).
Alternatively, you could get the Narwhal and it's trailer rigged for single person launching?