I assume you want to use an anime character for Genesis right?
I think what you will want to buy depends on the type of “anime” you like. HItomi is one style, but you also have the option of Amy, Jasmin, Nata, Chibi girl, or Aiko3, Aiko4 and the Girl when you are using genesis. You have to buy them of course, but they all have different looks. (there are probably a few I am missing so forgive me)
Hitomi is the most supported toon for genesis. She has her own UV mapping setup so there are few texture packs available that will only work if you have her installed. There are also expression and pose packs optimized for her as well. The expressions and poses can be used on other Genesis figures, but typically need some tweaking to work correctly. Hitomi can use regular genesis expressions but again you will need to tweak them to look correct.
Just like any Genesis figure you can blend Hitomi’s shape with other genesis shapes so you aren’t limited to her stock look. Hitomi also has the most morph dials out of any of the toons for genesis, she’s got nice selection of facial dials and a couple for her boobs too. Will depend if you like that style of breast though.
As far as other toon/anime females for genesis none of them have much in regards to morphs but they can be mixed with other genesis morphs you have. Typically they have a body shape dial and a head shape dial so you can have anywhere from 0 to 100% of the shape. Hitomi is the only one that actually has morphs to let you adjust her cheeks, chin, eye slant etc. Nata is the only other toon I can think of that has any additional dials, and that is to close her lips because her smile is curved.
By herself Hitomi is pretty neat, but to do what you want you will still need to mix with the genesis figures that are available. Victoria 5 and Hitomi might give you almost everything you need. Or instead of victoria 5 you can get some free shapes or other kits that will give Genesis more dials. Genesis comes with a basic child morph that you can use along with these shapes if you want. Victoria 5 has some decent breasts morphs but I prefer using V4 breast morphs that I have transferred to Genesis myself.
[edited to add more details, correct spelling and to add whitespace]