We've recently taken delivery of a Redbay Stormforce 11 cabin RIB for use as a VIP transfer boat on the Thames. The only slight trouble we've found with it so far is the lack of visibility in the rear quarters. This wouldn't normally be a problem, but when you're manoeuvring in tight spaces with a fast current running through with lots of other boats nearby whilst trying to line up a boarding platform on the back of the boat with a 3 ft wide gate on a pier it gets a bit tricky!
I'm trying to track down a pair of wing mirrors that we can fit to make life easier. My search on ebay has been fruitless.
Maxi is right... indeed most of the tools you need are probably already on the boat. Certainly the 11m I had the fun to drive had engine bay camera and as i recall a camera providing a rear view so you could check nobody had fallen off the back etc already in place - and nicely displayed on one of the plotter screens.