The covers are made to accommodate consoles etc. Personally I've got a 5m rib with a console probably about 2 foot high, or more, (not measured it) and the cover is fine, I went for a 20 to 22 foot cover. They are elasticated and fasten over and under the boat to get a good fit. The A frame is a problem, but then that's up to you to decide if you want to cut it to accommodate etc.
Mine fits to just under the tubes and is fine, (sorry no photo to hand)
If I was you I'd mail them with your dimensions and ask for advice there, I'd guess they are well used to this type of query.