Didn't know where else to put this, but this page:
http://saito7.jp/sampler/fdd_PC.html (http://saito7.jp/sampler/fdd_PC.html)
if you translate it has VERY helpful instructions for getting just about any modern floppy drive to work in old samplers that use non standard floppy drives or 720k drives.
Apart from the feckin Casio FZ1, which appears to be the most non-standard floppy drive arrangement ever produced.
I like the look of these http://lotharek.pl/product.php?pid=12 (http://lotharek.pl/product.php?pid=12) and the SD card one that they sell, but its a pricey chance to take to see if it'd work on whatever you have.