I want to open an on line shop selling MP4 video files. I also want the shop
to have various one minute MP4 clips of each file which will be in way of
introducing the potential customer to that particular file and the clips
shall be available to freely download.

Initially I intend the shop to have around 100GB of file space, but I want
to have the facility to add more files (and therefore size) at a later date.

After the start up of the on line shop I want the visitors that have
purchased a download of one or more of the MP4 files to be able to register
with a forum that'll be part of the web site. I would need to administer all
postings to the site prior to the posting being able to be viewed by the
outside world. Similarly I want the customer to be able to upload any
relevant clips that they have for possible addition to later MP4 files, once
again I'd want to administer the uploaded clips prior to outside viewing.

Advice is needed -

a) An ISP that will offer the technical ability to create such an
on line shop

b) An ISP that will offer hosting of a large video content that
will grow and develop over time