Apache 2 should work, I still prefer the 1.3 series, just because it works and there aren't any issues really. I do run Apache 2 with PHP5 on a testbox, and it seems to be stable.
Btw, one thing you can do is use a php script on the BSD box (assuming that's your public webserver) to retrieve the data from a php script on the windows box. This way you don't have to expost the HS box to the internet. I do this exact same thing.