Although I have a great deal of opinions on which TGP software is the best for each type of situation, I would have to agree with juicylinks.
Running it on windows means more overhead costs (hosting is usually at least 25% more expensive for windows servers). Futhermore, most of the internet community developes for Unix based systems which means greater support is available.
If you are just starting this TGP take the time and get a Unix host (FreeBSD is best IMHO). The ask your question again
.