Hi Red
Just a question, has the RIB already got a frame fitted, and if so has it been designed for self righting ?.
Most A frames are not strong enough or the mounting to the hull strong enough for self righting.
If your looking at buying the frame as well you may need to beef up the mounting point to the deck/transom to take the loads imposed.
Maybe teaching my granny to suck eggs, but just in case
Regards Gary