I want to set up an online t-shirt store. Basically, I want to sell t-shirts online to a niche segment(fixed designs) in only India(but may expand world wide if it works). I would need a shopping cart + online payment + order status inquiry system. I want the site to be simple and minimalist.<p>Should I develop a custom web application or this can be done through some open source software/SAAS?<p>Recommend which open source applications I can use for this purpose.