Hey!
I'm currently working on a couple of videos tutorial for a 3D modeling tool. I want to open a website which will host these videos and possibly some other related things as well. The idea right now is to have several shorter clips available for free streaming on the web site and a full download for a yet to be determined price.

The videos sizes will be quite large- ranging between 500mb-1GB each. If I want to make them available in one file the file size will obviously be even larger.

I'm quite new to the web hosting world so my questions are as followed:

1. Are shared web hosts sufficient for my needs (file hosting of large files, selling the video files online using paypal, streaming video etc.)
I looked into VPS but that just confused me even more. Take at Starlogic for example. On their homepage they promote 3 different deals. Looking at the ProLogic and VPSLogic I would think that Pro is better than VPS. For instance, they say they provide unlimited GB storage and transfer whereas the VPS deal provides only 20GB of storage and 1TB of transfer and for a greater price (30$ per month vs 6$ Per month).
I take it that storage space means how much I can upload and transfer means data transfer which would be used for downloading those files.
What's the difference between the two and what is required for my needs?

2. Would the desired process of selling the large file be complicated either for me to set up or for the consumer to download?

I'm going to get someone to help me set up the web site once I'm ready for it, unless I manage to pick it up on my own but I'll cross that bridge when I reach it.

Thanks in advance!