yup, the windows part is not really avoidable, I would think going linux, but that would be learning to many things at once.
I need to be able to get to it via lan (over VPN on an ADSL connection) to add songs to it and thats not something I can really do on linux with my current knowledge.
The budget may have extended to a small touchscreen like you would have in a car, but not 100% sure yet. - In any case, DOS is not really an option due to drive space considerations too