40th b-day bash -- WeHo?

So my friend is turning 40, and needs to go someplace where she can be surrounded by all her friends and reminded how hot she is despite being an old married lady with a baby. But she's paralyzed with indecision and I've volunteered to organize the bash...even though I live in NYC. Mayday!

My must-haves:

1) Low-key, funky, on the cusp of dive-y
2) Bar or bar/restaurant big enough to accommodate 20-30 people (although probably not at once) where people can get nibbles if needed.
3) Location: Prefer West Hollywood but am willing to be steered elsewhere

I know the birthday girl loves Cha Cha Cha (as do I; it's sort of what I am envisioning, but don't know if it's big enough?). She also adores sushi. From my review of previous posts, some contenders appear to include: Blowfish, Bowery, Casita del Campo, Cobra Lily, Fat Fish, Geisha House, Hungry Cat, Musso & Frank's, and Tangier.

Please help me give my friend the party she deserves! Thanks so much....

nycfille in Los Angeles Area