You can get the Honda spacers at their stealership and then gring down the extra "nub" that is there. Other people have bought washers at Home Depot (Which looks ghetto). I have also heard of people that go to a metal supply shop and purchase a small piece of aluminum round stock and drill the hole in the center via drillpress.
I'd say either go to Honda or check eBay... Actually, I think someone on the forum sells them... Check out the search button for that one as I'm not 100% sure if it was on this forum or not.