Networking & wireless: Development of Ringtone site

Development of Ringtone site

Hello,

I would like to develop a site that will allow users to download ringtones which are listed on the site to their mobile phones--a rather smaller version of a site such as Jamster.

While I am able to record and digitize these ringtones, I am new to the area of web development, and am looking for information on what type of web developer or company could assist in the development of such a site--it would not seem to be a simple web design company, as they would also seem to need to have knowledge about text messaging, telecommunications in general and compatibility with cell phones.

It seems that what is necessary is:

Recording
Digitization
Uploading to site
Ability for users to preview
Ability for users to download to phones via text messaging/SMS and/or some other format
A per-download ability to charge ( I don't plan to use the rather shady monthly formats that seem to prevelant in this area)
The usual sort of shopping cart/payment set up

Any thoughts on a) how to set this up; b) useful people to talk to who might more knowledeg about this that me; c) sites or forums that may have information on such site development?

Many thanks.