Starting a Photo Stock Site

I am a photographer that would like to start my own stock photo site. I have an existing site I was considering using an off the shelf product like ktools Photostore. I really know nothing about web design or hosting. My goal is to have a stock site that can accomodate a few thousand images offering lo and hires files (up to 50-60 megs). Do I need to have a dedicated server to do this? What kind of cost am I looking at to get a seamless site going? Thanksfor your help.