By far the best script I've seen is the Fresh Store Builder created by Carey. This guy knows what he's doing, he's been created small niche web stores for the last 3 years and recently opened up his script to the public.
For a fairly reasonable one time fee you can get an unlimited license to create as many stores as you like.
One great benefit of the Fresh Store Builder is its optimization for the Search Engines. Not only is it SEO friendly, it will include all the metadata for on-page SEO to help you rank high in Google Search Engine results, bringing you more targeted customers.
