my wife loves the smokey and miho eps. what might you recommend for her?

what she likes about them: super chill, mostly acoustic.

i like some of what i've heard of astrud gilberto... what is her best album?

but for god's sake, no latinized standards.

I would recommend a (Brazilian) group I heard about from the folks at Dusty Groove called Quarteto Em Cy. I think it fits your description pretty spot-on, and the blend of the 4 womens' voices is phenomenal.

Dusty Groove offerings