Build a website that allows me to drag and drop objects to build.

Check out our current website [login to view URL] We have several products like gangways and ladders. I would like this to be simple to use. Dragging and dropping items into place and it outputting price and other info. A button that allows the customer to send it directly to our email. the docks are 2' x 4' pieces held to gather by 4/4 3/4 2/4 and 1/4 connectors. We also have 2' x 2' pieces and 45 degree angle pieces. You can see them all under products on our website. I would like a 2D top view of those in a side bar. I would like them to be able to drag the product from the side bar and connect them together. After they are done building they can click a button and tell them how much money its going to be. The prices of each i can get you. How many of each 4/4 3/4 2/4 and 1/4 connectors are needed. They then can enter their Zip code and email and send it to our email. And tell me how many bolts are needed. Each dock piece has a certain number of bolts. Shouldn't be to hard to do. And when they drag the gangway (a walkway from land to dock) over it pulls up a menu on how long they want it. Then when its all built it can add up the prices of everything and show them. Just basic rectangles work for the 2d top view.