Honestly, I just can not handle processing prints. I'll be busy and college and can't worry about having to print and ship orders. Sorry. That's why I asked about Smug and Zen.
You will be editing the pictures, right? Why not use a lab like WHCC or Color Inc to fulfill the orders but they print and package them and you have them drop-shipped to your client.
I mean, yeah, you have one more step - placing the order through the lab, but you never touch the prints or need boxes or anything - they do it all for you. The only thing you would need is a shopping cart on your website. I personally use PhotoCart, works great.
It goes like this - I edit images and put them up on my site. My clients shop with the shopping cart. When they are done, the money comes to me (no cut in my sales), I get a Notification of Payment Received, and then I look at their order, upload the images to the lab. I could have them packaged pretty and drop shipped straight to the client.