If you are going to keep the LA address for DishHD I would recommend the following:
24" for 119
36" for 110
1.2m for 129
As for OTA, the Maui stations are repeaters for the Honolulu stations and will mostly "Flash Cut" from analog to digital in Feb. '09. None of the stations is currently broadcasting digitally on Maui.
If you wish to stay with Dish but want the Hawaii HD Pack, you can use the 722 but will be limited to 8 channels(ESPN, ESPN2, TNT, HD Theater, HDNet, HDN Movies, Univ. HD and NFL Net HD) HBO and SHO HD are also available. Dish does offer the Honolulu stations in HD (ABC, CBS, FOX, PBS and MyNet) minus NBC. If on the SD side you are only using AT100 or AT200 the dish for 110 can be as small as 30", but if you want AT250 36" is needed.
For Directv you can get all the HD channels that available on the mainland but requires using 2 1.2m dishes. Directv also offers the Honolulu HD stations but only ABC, CBS, FOX and PBS.
On Maui, Oceanic Time Warner Cable is available island-wide and offers a HD package of 25 channels plus offers the HD channels from Honolulu of ABC, CBS, FOX, NBC and PBS. Oceanic prices can be steep in that they require Digital Cable for a HD box plus have implemented SDV so a TivoHD box will only get the locals(via CableCARD).
Hope this helps you out.
Charles