I've got an 18' Polaris RIB with a Yam 115. Console is set back so the pilot bench is attached to the transom.
Boat is definitely stern-heavy, but it is not at all dangerous. Engine trim is enough to bring the nose down except right at the on-plane transition, which is pretty quick.
I toyed with the thought of trim tabs, but figured that I don't really need them at this point. Maybe later, after I get other, higher-on-the-list toys.
Good luck with your Ribcraft; that was another I was looking at.