Try giving them more light. At least that will slow down or stop the elongation.

Chop it a few inches below some leaves & re-root it. They are known to get leggy. I have some growing in a hanging basket...like they think they belong there! LOL

They're in a south-facing window AND they're under a grow light... Do they still need more light? D:

I will probably chop it once a couple more leaves fall off. I'm a little nervous just because I don't want to risk killing it and that seems like my kind of luck, to do a standard plant beheading and have it die on me... I can't chop the echeveria though because it's getting tall, but the leaves are evenly spaced and it just wouldn't look nice even if I chopped the top off.

Wait... really? Direct sun light through a window and grow lights? Or, do the eaves of your house prevent full sun shining through south facing windows?

Not really... there are trees around but they still get at least a couple hours of direct sun. The only other thing I can think of is that they're not really graptosedums (I got them at Home Depot and I don't really trust their succulent knowledge since they keep them all inside on dark shelves), but I don't know whether that would affect how tall they get or how stretched they look. Every other picture I've seen of similar plants (various graptoveria/graptosedums and echeverias) shows these cute little compact rosettes, and mine are all stretchy and weird looking. It's kind of disappointing actually because I don't know why they're like that.