I know I'm a little late for this post, but I've done a lot of reaserch on the carburetor forums relating to conversion "kits". There's a lot more negative than positive on kits. If you really have a handle on carb builds, you could get E85 specific blocks and build your own kit. I thought about it, but didn't understand how to configure the emulsion bleeds, tranfer slot bleeds...ect. There's a lot more to it than metering blocks and jets.
I too contacted Eric at Horsepower Innovations and had a new carb built. He knew it was going on a street car, so it was actually calibrated on a street car. The carb was spot on, just needed a slight mixture adjustment.