Michele Roderiguez might be fine, b/c she's a really tough chick.....which is essentially what Montoya is. I'd be fine with JLO....only she's kinda like Box Office poison. Not down with Longoria, Hayek might be too much latina.....her accent is so thick, whereas Montoya seems to always have been more like what JLO is, which is an American born and raised latina.
I still gotta go with Elizabeth Rodriguez. She was a tough chick as Gina in Miami Vice, and really....Montoya would probably be alot like Gina, not a character that gets alot of screentime but still has a presence. Marisol Nichols, a mexican-decent actress who played a cop on BLIND JUSTICE could work too.
If you cast any of those women......your kinda dooming yourself to having to MUST use them more than you probably would want to. Suddenly, b/c you got Hayek.....or Longoria....b/c of they're status, you gotta beef up screentime or get lashed with some critcism over it.