I am interested in sharing with others information about which SL stores supply fitmesh clothing suitable for female avatars up to the maximum size of breast in the standard mesh avatar by TMP (The Mesh Project). From my trying of various demos and some of my own purchases, it seems that some fitmesh only 'stretches' over smaller boobs after which they then disappear inside the avatar; while other fitmesh truly adapts to the curves of any avatar.
Two stores whose fitmesh does suit max size breasts are:
L.I.C. (aka Lyndy in Chains) - https://marketplace.secondlife.com/stores/155645