Bolto-

Welcome aboard to FlyerTalk, but I must warn you this can be very addicting

If your planning a trip to Hawaii via Delta with your skymiles it will take 30K each to get you an your wife there, unfortunatly you cannot combine miles btwn accts but.....

you can accrue more miles by signing up for the American Express skymiles card and earn up to 15K miles fo new members (depending upon which card you apply for; gold,platinum etc.), you can also earn 2K miles for signing up w/MCI long distance through Delta's website, with car rentals and hotel partners.
These are just a few options and you can find many more by going to Delta's website> click on skymiles> membership guide & program rules> earning mileage

If time is a factor you can always purchase the addt'l miles needed in increments of 1,000 for $25, up to 9,000 miles; only when redeeming a reward (good for travel in US and Canada only(not sure if this applies to HI.)

My husband and I went to Hawaii last year (maui) and I'll be glad to help in any way I can

Aloha!