Good question. Dinks are a tough subject. I have had 4 (I think) so far and have not found the perfect one yet. The RIB is by far the most useful, durable, fun and easy to tow. If you are going to bring it along for short cruising in the bay than towing is a reasonable option.
All you need to do is inflate a dink once on deck and you will realize how difficult it is. Inflatable floor is a cool idea as it saves weight, but if you deflate it it is just more to inflate and beaching can cause damage. Tinker is another option.
Whatever you get I doubt it will be your last, so you might go cheaper with used.
Some questions you might want to answer for yourself.
Do you want to park the boat at
anchor and go touring in the dink? - get a RIB and a big engine.
Do you plan on multi day passages offshore on a 30 footer? - go small roll-up and small engine.
Do you plan on running around the home harbor with your dink and plan on keeping at your boat? Get the RIB setup OR get a sailing dink, walker bay or Fatty knees.
Engines are a whole other subject, but I see a use for 2 for me, a lighter weight 5-6 hp and a 15hp cruiser.