In this forum page you can see an LPS hybrid.
viewtopic.php?f=5&t=2903&start=70I think LPS Blythe would be best as the little pullip head looks more adult than the body (the Dal looks best on 11 cm body but she has an upset expression XD ). I'm telling you that as I wanted my little pullip to be posable too but I gave up giving her a small body...
Anyhow this is only my opinion, I saw some little pullips hybrids that looked cute too! Maybe you just have to chose one with a most childlish face up. ^^