Yeah, you definitely don't want almost any of the rosetted species as your first tuberous, you will almost certainly kill them (I ruined both of my D. squamosa last year because soil issues, too much tannins). D. tubaestylis would be the one exception that I've found, and I might have some later in the year, but generally recommendations would be hookeri, auriculata, gunniana, menziesii, gracilis. The erect/climbing group is generally the easiest, both the rosetted and fan-leaved species more touchy (but the rosetted the most so).