Personally, I started in high school with Os Mutantes via my gf at the time who was a fan (and discovered them via the "Nuggets II" box, which had just been released). Given the strong US and UK influence, I think their stuff makes for a relatively easy transition for non-Brazilian listeners despite the experimental qualities. I mean, something like "A Minha Menina" basically just sounds like The Beatles singing in Portuguese, which was pretty much the whole point.
But since Tabs is into jazz and already diggin "Getz/Gilberto" and Jobim, he might wanna explore more Bossa and would possibly prefer some of the jazzier 70's MPB to tropicalia as well, like that Verocai. The Baden & Vinicius is also a good call but seeing as it's more traditional (for lack of a better term) I'd probably recommend that to someone who's a tad more familiar with Brazilian music- IIRC it's your favorite Brazilian album ever?