Well, I don't have to go through all of that, I don't think. I found a company that will customize one of their matrix processors so that it will recognize hits of less than 1ms.
So, for anyone in the mysterious future that Googles for this kind of thing - check out Hagstrom Electronics. The board I'm getting is the KE-USB24, but they have to modify it for me. Final cost, $155. Time saved by not having to re-learn electronics knowledge that's been gone for 10 years: Priceless :)
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Still, I'm saving this thread, because some day I probably will need something like this. Thanks so much for all your help!