I understand your problem. We're in Irving as well. My son is only 18 months old, though, so I still have a while to think about what to do.
I was a sub for Irving ISD, and I can tell you that the main problem with Kindergarten, is that they have entire classes full of kids that they have to teach English to. There were a few times when subbing at the elementary level that I wound up with a class full of kids that could not understand me.
A friend of mine is a 2nd grade teacher at Townley, and she said that they're a year behind most other ISDs, because of the "No child left behind" thing, they cannot move forward until everyone understands the last thing taught. Since in Kindergarten, many of the kids are preoccupied with learning English to have much room for anything else... it holds everyone up.
Now dont' get me wrong, I'm not trying to be anti-hispanic, or trying to knock the Hispanic community. I think that their children deserve a better education than they're getting, as well. I don't know what the soultion is... I just know that this is a real problem with Irving ISD and many others around the metroplex.
A good solution for you... might be looking into some of the local churches, I know that a few of them have private schools. If you find one of the smaller ones, they're usually relatively inexpensive.
Irving does have a transfer policy, but you have to get in there really fast. They only allow so many kids to transfer into each school. I know a few people that have had a really hard time transferring their children.
I hope that helps a bit, sorry I couldn't be more specific in my advice.