ASP is a windows thing, and no matter how horrible and blood-curdling it is, it runs best on NT servers.
They cost an arm and a leg and still give quationable performance, but it's more reliable than ASP on Apache through Chilisoft.
On the other hand, you could decide not to buy NT servers and use the cash to hire a PHP programmer to convert the ASP site to PHP. That will take time and money, but downtime costs more (and so will the new MS licences) and in the end you will be better off with PHP than with ASP.
A forum, a FAQ, what else do you need?