I want to create a website to sell printer ink and toner.

I want to have the visitor click on the brand then the type and then eventually the exact model.

I need it to be a shopping cart where they can choose the number of units times the price.  I need them to be able to pay for it on the way out and then the order to be sent to a drop ship company.

I need to be able to change the unit prices either individually or by a uniform percentage change.

I need there to be a multiple unit discount if they buy 3 or more to be a lower price.

At this time I will be selling ink and toner only, but I need it to be expandable to include other office supplies in the future.

Please see sample website that I would like to almost mirror. 

Look at the upper right "printer supply search" 

http://www.ldproducts.com/catalog.php?roi=echo3-5080331966-3538718-1008912313148081b9c869a6ddb7483e&path=landing&id=502&XID=ldnloct09&Coupon=FALL2009&position=17

There also should be pictures of the individual items next to the purchase line.

I could do the website without the picture files if it is too much.