Build an Online Store

I have no idea what exact skills this would require, but let me try and describe what I had in mind. My mother is knitting many different winter hats, she creates 2-3 per day and each one is different. My idea was to create a website generator, where one could choose or create the kind of knitted winter hat he/she wants. The main menu would include: "Home" (Description of the home business), "Create your own hat" (The generator), "Premade hats" (Examples of what people ordered) - also make an option here for sex: Male, Female or All, and maybe "Most popular" (This would include some hats my mother loves to make, it could also include hats which are in discount), "Contact information" (The association or company of my mother). So when you click on the "Create your own hat", on one side of the website there would be different options to choose from for your manualy created hat: colors, different styles, width, lenght, patterns, with pompoms, with ears, hello kitty style and many more,... (I will create an exact list of all the parameters, once someone accepts the job and tells me what way this would be made, that it's most practical and beautiful), while on the other side there would be a picture of the hat, you just chose from the parameters (I think this is the hard part). The picture of the hat should look somewhat real, but fun. The main purpose of the picture would be so the people can see what they are "building" or "creating". Once they choose some parameters and they like the picture of the hat, they've just built, then they could click order this hat and it would put it into the shoping cart, now they could create another hat or simply proceed to the checkout. On top of the site I'd also need a header with the possibilty to register an account. This is a fairly new idea of mine, so it still needs to be developed, but I'd love to speak to someone on Skype about the realization and what are the possiblities. I put the price on "Simple project", but I really have no idea how much such site could cost, so I'd need help with that too.