Thanks everyone for help (and for pm messages as well).
A RIB that fits the requirements (including budget) is a Bombard DB 600. Spent an hour on the water last Sunday - everything seemed to work. I was surprised by the boat's stability, I guess it's due to the tubes touching the water most of the time.
The only disappointment was lack of depth sounder - plotter fitted is Garmin 551 (without "S").
