hmm if you want a custom one, i think anazasi may be opening up the shop soon for orders again? i don't know - but that's where i got my sheet. Here is his Decal Sheet thread, or just pop him a PM.
if you want the official "blue" set, hasegawa put them out - look at the list of macross dealers we have in the "Where to Buy" forum, one of them might have them still. if you want the "pink" minmay guard set, it comes packaged with the actual hasegawa model kit, which i think Monkey Nugget just got a re-order of, an some other dealers will probably have this set on hand as well. good luck with your Minmay hunting!