If you're going inside the wrecks with the Truk Odyssey Guides next winter, I recommend both you & The Wife have at least conventional 40 to 50" long Octopus Regulator configuration -and not the inline type with your inflator hose. You need some "stand-off"/maneuver length slack if you gotta emergency air share inside the wreck while egressing smartly (with non-silting frog kicks and good buoyancy/BCD control -i.e. hard to operate inflator-deflator while breathing inline BCD octo reg setup) down a long narrow corridor, single file.
The best setup for overheads is the Long Hose Primary Reg for emergency donation, and the bungee'd necklaced Back-up around your neck & hanging below the chin. Again recommend taking at least a short pool workshop with
Boulderjohn to learn how to use the Long Hose configurarion.