White linen suits are more difficult to find than you might imagine. I have two of them. One I got at Perlis, a men's store in New Orleans. The other I got at JC Penney's of all places, in Carlsbad, California. The one at Perlis was pricey, but fit beautifully until I had too many loco mocos. Then I got one at JC Penney's. The Penney's one I had to have tailored. The Perlis suit only required minor tailoring. The tailoring for the Penney's suit was almost as much as the suit, which was about $125. The Penney's suit is really inferior to the one from Perlis. There is no lining whatsoever. Can't wear colored boxers or briefs with it. Everything shows. The Perlis one is beautfully lined and tailored. Both, though, are made in Mexico where these are popular. These are so hard to find that I keep my eye out for them at all times. I have never lived in a cold climate, and the dark suits are ridiculous in warm places like San Diego, New Orleans, or Hawaii. When you wear one in normal circumstances, which I often do, it is startling to people, although it makes all the sense in the world.
It is easier to find TAN linen or cotton suits. Often times stores will refer to a suit as "white" when it is really beige or light tan, or cream colored. Pure wedding white is challenging even on the mainland. You CAN get these online. Perlis has them.
http://www.perlis.com/product_info.php?cPath=9_12&products_id=147
As to your actual question, I have no idea where you would get these on island. I would start at Macy's and then move on to the shops at Waikoloa. Season is changing on the mainland and so YOU must change, too, even though your season is not changing.
In the meantime, for your entertainment, here is a picture of me in New Orleans in my Perlis suit. Please note that I am wearing a
white pearl tie . I found the tie in a junk shop here in California: $10.
http://www.flickr.com/photos/punaguy/3277461839/
My desire is to wear my suit in Hilo for the White Linen Night. Might miss it this year. Not sure yet. In any case, I will be wearing the Perlis suit when I do, god willing!