Just a minor update on this:the Intersil ISL3035E is just about perfect. It appears to be essentially a MAX13035E in a slightly different package (3x3mm QFN-16 instead of 4x4mm QFN-16) and for a third of the price.
The bad news is that it's an obsolete part and it's not recommended for new designs. Digikey's got five hundred or so (and no stock of the even smaller 2.6x1.8mm QFN-16 version).
If you're just doing a one-off board, this is probably perfect. Easily affordable and purpose-built for the SD level conversion task. If you're doing a production run, you should have no trouble reworking the board for the Maxim chip instead (same pinout, just a 1mm larger in each dimension). Unfortunately you can't put one footprint inside the other to support both, because the Maxim one's got an exposed pad on the bottom.