Something That Will Allow Me To Sell Files Like iTunes?

Hi, I’m trying to gather information on how I can start my wordpress site where I intend to sell MIDI files in an online store. I basically write melodies for DAW MIDI Sequencers (i.e. Ableton, Logic, etc) and would like to have a section of the site where I can sell these for say $1.00 each. Naturally, I’m thinking of something along the lines of how iTunes lays out their store but obviously much smaller. I’d like to make it so a customer can add MIDI files as he/she pleases and then go through a checkout as opposed to on iTunes you’re charged right away when you buy a song. The reason I draw a comparison to iTunes is because I’ll be selling files similar in size to .mp3 (.mid) as well as the fact I’ll need to be able to list several hundred – if not eventually thousands of MIDI files.

I know this may be a multi tiered question and there may not be a plugin that can handle this concept, but any partial input to an answer would be greatly appreciated.

Thanks so much in advance to anyone that takes the time to help me out! 🙂