Web Hosting needed with high bandwidth ASAP

I need ASAP the following:

2 to 5GB of web space,10-30 GB data transfers per month, Hosting on Windows + mySQL or LAMP but able to support .NET applications on hosted site.
In future, i need to have ecommerce and audio/video podcasting features so support for these is needed. Also there should be flexibility to run audio and video ads on the website.
I need scalability details so that rampup in web space and bandwidth is possible.