Hello! Welcome to UtaForum!
if you want some utaus, i'd recommend searching for Ritsu Namine, Ruko Yokune, Momo Momone, Nukupoid, Ryu Drakita, Berry Shake (also by Ryu Drakita), and, well, my Utauloid, MODUKO.
These are some of my favorites, but the utau world has sooooooo many more utaus...