Need help creating multi item + drop down buy now button!!!

[QuickCleanPC]

My website sells computers and on the page i need to place a buy now button needs to beable to select parts.

Let me be clear about what it is that I do need. I require a drop down list  for each part. When I say dropdown list for each part, I do not mean each one as an option for one item to sell, I am meaning that I need a multiple drop down list for each item, not options for one item.

Lets say there are 12 parts (items) that make up a computer, each catogory such as the CPU, GPU, Ram, Powersupply, Case, Speakers and more, need to have a drop downlist per catogory. To be more specific, lets say with in the CPU and Ram catogory I may want to select either a Intel Core i3, i5 or i7 and as far as the ram, I may want to choose also either 4GB's to 16GB's of ram. I have tried and tried to make this work but no luck . So I am asking please will some one help me. My website has the best intentions and our goal is to be the best, we wont stop till we are! Please if you can make a functional working code for me we will not only be truely greatful but we will give you a large discount.

Example:

• = 1 drop down item + options): 

# = item (item option)

Colors for identification.

<-------------------------------------------------------------->

• CPU

1. Intel Core i3      $100 (default selection)
2. Intel Core i5      $200
3. Intel Core i7      $550
4. ....

• Ram

1. DDr3 4GB's 1066MHz      $50
2. DDr3 4GB's 1333MHz      $50
3. DDr3 4GB's 1600MHz      $50

Quantity:

1

2

3

....

And so on...

• Power Supply

• Video Card(s)

• Tower Case

• Monitors

Weight: 40lbs.

Tax: 5%

Discount: 5%

Shipping & Handling: $50.00

(BUY NOW)

<-------------------------------------------------------------->

Additional info: 

Currency: USD

Paypal email: QuickCleanPCcomp (at) gmail.com

Website: computersolutions.spruz.com