It is - D. spatulata "Kanto", at least that's how the seeds were labelled (via the ICPS seed bank). They trend *very* red compared to the other spatulata varieties I currently have growing.
As for a proper media, I grow most all of mine in a mix of chopped LFS and sand (generally shoot for a mix of around 40/60). However that clump is growing in, as you said, just an ugly pile of LFS (started them in it as leaf cuttings about a year ago). They seem to be trucking along just fine, and I'm too lazy to try and dig them all out of it now.
@Whimgrinder: Nice aliciae indeed! I started some from seed recently, but they're still just specks in a pot at this point.