I scaled some drawings of an S-3 and A-6 and found that an A-6 can carry about 30 sonobuoys just forward of the arrestor hook. Normal A-6 drop tanks could carry about 20 a piece so add a pair of them and you have a worthwhile load of 70. This would still allowing for normal drop tanks and/or weaponry to be carried and longer range missions to be flown with the fuselage buoys only. Versatility is always a good thing especially when it's fairly easy to implement.
How about an unmanned tanker version for the USN, perhaps even returned from the graveyard, re-engined, re-winged and filled to the brim with fuel.
Perhaps made from a Prowler, with the longer fuse? Wiki says that's an extra 5ft of fuel...
I like your thinking. A KQ-6 uninhabited carrier based tanker would be cool.
I like it! I'd swap out the vertical stab for a standard one for looks.