Someone else has heard of Nancarrow! I love his stuff!
Though the best places to start with Nancarrow are probably studies #3 (the "Boogie-Woogie Suite", which is relatively conventional and jazzy) and #48 (probably the culmination of his late style, with some of his most exciting ideas and a structure that is both ingenious and relatively accessible).
Sorry, that's probably not the response you were hoping for. Or maybe it was, dunno.
I only discovered him this week while I was reading something else and decided to check him out. Putting him against an Atlasian seemed too delicious not to do. I've listened through most of his stuff from #1 to #40 (the rest are difficult to find on youtube unfortunately). So far I approve.