Unless something has very recently changed, there are no Reserve P-3 squadrons in HI. Just Whidbey and Jax. That said, yes, you start talking to the host unit first to start networking. You'd then apply to one of their pilot selection boards which will require you to prove that you would be released and able to join the unit. Historically, getting someone from another service over the Reserve Navy active duty side has been very painful and takes much longer than it should. However, if you're already getting out and you're just applying to SELRES, the process may be a bit easier.
All that said, some things to consider: The gaining command is going to want to get value out of you with the least amount of investment. If you have no ASW experience, that means much more time to train (which equals $ for orders) both at the RAG and in the squadron. If there are other applicants, and all other things being equal, they may lean towards taking the prior VP guy before you.
I'd look at VR, as well, for you. That's another option and has locations at all the Navy fleet concentration areas.
