I think the ridgeless double basket is the one that's usually called an "LM" ridgeless (as you say, it's not LM). This one you can get from espresso parts (
here), and they also are making an "
HQ"
version of it now. I got one of those recently but I haven't spent a lot of time with it yet. Regarding the ridgeless triple basket, I do not think it's usually associated with La Marzocco, but rather Synesso. EPNW sells this one (
here), as well as an "HQ" version of it (
here).
As it happens, Synesso's ridgeless double and triple baskets are very similar if not identical to both of these baskets. You can buy them from
Synesso directly as well.
I've liked both of these baskets (the regular versions, not the HQs—I don't have enough experience with those to say much of use about them) a lot. The ridgeless 14g one was my go-to basket for a very long time. I've moved on to usually using the VST since it came out, with great results for my coffee prep style.