I'd build my packages using MS VC++ 7 so as to be compatible with the AS 64-bit builds
MSVC++ 7 is 32-bit only. It's the "Microsoft Platform SDK for Windows Server 2003 R2" that you want for 64-bit compatibility with ActivePerl, and I recall you had difficulty tracking it down when you went looking for it last time. Afaik it *is* still available - if you think it might be worth the effort try this link.