RIBs tend to be more money than comparable speedboats, but you get what you pay for in terms of safety and all weather usability.
I suspect from what you are saying that you want something that will perform like the speedboat you mention, but with the added safety that a RIB brings, allowing more use over the year. Add in taking your wife and daughter out, and I get the feeling you are looking for a RIB with a little space and the ability to cope with a bit of chop in reasonable comfort - nothing much more.
The smaller RIBs will cope with a great deal, but I suspect they will be too uncomfortable and short on length and space, especially if you are using them at sea rather than on a lake? I reckon an ideal boat might be around the 5.5 - 6.0 metre (90hp-ish upwards) range for comfort and overall usability, but given your level of experience, cost and garage constraints, nearer 5.0 metre/ 60hp plus would work for you better. You may find your budget stretched here though! Loads of good boats to choose from though - Ribcraft, Humber, Tornado, XS, Avon, etc - all make good solid boats.
RIBs are inherently safer than speedboats, but will you be using it in the kind of conditions that warrant the extra ability? perhaps a speedboat would fit the bill?? I would suggest that a test drive of a few RIBs and speed boats in the conditions you want to use them would be a good start point, although bear in mind, as you get more experience, you may find the RIB suits your growing confidence better!