I went Googling to see what's going on in the breast attachment world. (Sad to do that rather than going in-world and searching, but I suspected that the trend to Marketplace-only sales thanks to SL's outrageous land prices is still underway.)
With the fitted mesh option open, I went looking for "mesh breasts". Sure enough, there are several sources of fitted mesh breasts. (There are also non-fitted mesh breasts out there--you can scale non-fitted meshes, but the fitted ones are controlled by the relevant avatar sliders. I'll have to try both kinds, of course!)
I must say the video for the Cherry Bomb fitted mesh breasts is very impressive. My only quibble with it is the way the model's hands are positioned over the breasts at a couple of points; as a potential customer I don't want things hidden. Responding to avatar sliders is a wonderful thing; I like having control over buoyancy and cleavage. OTOH, will the size slider give me the size I want? I know me; the answer, of course, is "no", but it's a matter of tradeoffs. After all, fitted mesh allows jiggle.
I don't wish to slight other makers or products, but I will say I hope that they come out with videos as well.
Is it my imagination, or is Tango compatibility the main, if not only, breast attachment support new clothing has nowadays?
A surprising amount of other things showed up in a marketplace search for mesh breasts, much of which I was happy to see--AOs that mentioned breast attachment compatibility as a selling point, clothing and hair... and, oddly enough, a set of mesh additional arms if you want to release your inner Hindu goddess. (I have the two "Kali" sets; they don't move, but they're nice when you want ten arms. If only I hadn't read about the thousand-armed goddess of mercy, I might be satisfied... :))