I'd say you're plan is sound...although another option might be HEAVY DUTY anchored points and ratchet straps especially if only a couple of sets of gear?...ultimately everyone configures their own RIB to suit themselves and thier usage.
If you need a Rack and with keeping the Camping option it's probably a forgone conclusion anyway...plenty Lager Ribs do have passenger seating in front of the Consul with little or no detriment...although the Consul (may) be but a little more aft.
The High Bow sheer on the Delta and its overall size will help together with heavyish engine may well will help ballance the RIG with forward mounted Bottle Rack.....
Weight towards the aft of any RIB is to be avoided ...whereas weight on the nose is only really of consequence in a BIG following seas when stuffing the Bow off a "Biggie" is the Danger .....when you probably won't be diveing anyway
I dived in all sorts of weather for years in RIBs some a lot smaller ...who didn't even have a Bottle Rack....we got by.
Go for it