Hello
Yes, exactly this was my feels too 😀 (I love anime style, but not in roleplaying games).
The early models allowed changeing eyes, but the newer ones not. the reason is simple: the skull’s anatomy, faces are differents, the eyes are on different size, shape, angle, etc. BUT if you want change the eyes, its really easy, you can do that in many way, i will make a short tutor about it.
The portrait generator is on my “to do” list, it will focusing to making portrait, i think it will fill your desires more in this things.
If you allow me, i would suggest to Daz Studio, instead Poser, probably a little bit more easy, or you can hire me too 😀
(and if you need any help into them, just let me know 🙂
(And i not cup of my tea, but you can also can make a try with Make Human (it’s also free).