the traditional Hawaiian quilts are solid on solid background. The echo quilting would be time consuming in handwork. the ones i saw while i was over there, had the quilting very close together (1/4-1/2"). Obviously with some batting that wouldn't be necessary, though i probably wouldn't go beyond 3/4" just because the quilting is a big part of the design feature.
There is a wonderful series on Hawaiian quilting that has the patterns available from the Bishop Museum Bookstore in Honolulu. I'm willing to bet you could order one or more of the 4 books of patterns.
The Breadfruit pattern is traditional for prosperity and isn't too hard. Or as you said, you could do a series of the simpler ones in patchwork, which isn't something i have seen done before.
you can also order patterns for pillows from FabricMart in Honolulu, several of those could become quilt focuses.
i now have several patterns from their and two of the books for the Bucket List of quilts before i pass on list.