HI is tough but Oct is a little easier, you need to start now to give yourself the best chance of success. There are several issues and several approaches you can take. If you're happy with a studio I assume that means there will be no more than 2 people and you won't do a lot of cooking. Certainly the 1 BR is a better deal but you will have a much better chance of success if you will accept studios.
Assuming 2 weeks in a studio, here's what I'd do. I'd start 2 searches over all the weeks you can go listing the same weeks and complementary resorts on both (Maui one one, Kauai & Oahu on the other for example). Have them put a note on BOTH requests that you are searching for 2 weeks but do not make it two or none, take one at a time. Further instruct them that when you get one week you want to remove that island from your request and drop any weeks that will no longer work for you. And once you get your air, which I'd go ahead and do when you get what looks good to you, change your search or searches again accordingly. IF you have to get your air before you get your matches, a likelihood, schedule in to HNL on Fri and out of HNL on Sunday. That way you'll have more options of weeks you could possibly match to. Once you get one week tell MS if you will or will not accept a second week that overlaps a day or two or that has a gap between weeks.
You could either search for a studio saying you'll take a 1 BR or vice versa or you could set up searches separately for a 1 BR and a studio and tell them you don't want both, they'll know how to do that. Personally Id list all Marriotts that have the smaller units (Maui, KoOlina, Kauai BC), the Westin and Kaanapali Beach Club. If you want to list second tier resorts you can do so either now or later.
