>>5412222You don't want masks, you want shoulder parts.
This means CCBS Hero Factory/Star Wars shoulders, Nuva shoulders, or Knight's Kingdom rounded shoulder armor.
There's a lot of ways to do tits. Velken69, DawnofNSSD, Hugebricks, and Vezonisme are all good names to look at for inspiration and on occasion actual instructions that you can use to make your lady with giant tits.
On Bricklink this translates into the Bionicle, Hero Factory, and Large Figure Part parts sections as being your most useful when picking out ass n' tiddy parts.