Sure... I've never been asked to consult on our stuff, and in any case, I don't do web front-ends (one of the nice things about working with a team of other consultants). AFAIK IIS will happily talk to PostgreSQL (though maybe I'm wrong there...)
iis (yeah, asp in a successfull productive environement hehe) & postgresql works even better for us than iis & mssql :-)
- thomas