I got a kimono pattern from Simplicity's Costume section. While I understand that it's costume-ish and I would get flamed by hardcore lolita's for making a wa-loli out of it, I figured the robe part of the Simplicity pattern is just as good as any real kimono pattern you might find. It's a frigging robe, for crying out loud. :P
The only difference between a real kimono pattern and a costume one is that the costume one uses lazy obi's :P I'm actually quite fine with that. I mean, not being born into the Japanese culture means that I'll probably never be able to get the obi knot thing right. So instead of having someone criticize on how my obi knot could've looked better, I'm just gonna stick to a hook-and-eye, easy to put on obi, kthnx.
But anyway, that's just my 2 cents. If you could find a real kimono pattern for your wa-loli, then go for it. I look forward to seeing your wa-loli dress! :3