HELP PLEASE

I am trying to figure out how to add our products and I have two issues. First is how can I set it up to sell based on 2 measurements?



Like:

20" length

20" width



Based on .08 per sq inch or what ever we set? I would like to get it down to the fraction 1/4 5/8 etc if I can like we have in our current shopping cart seen here Custom Made High Quality Table Pads - Berger's Table Pads if you add a product and go though the shopping cart we need it to work something like that and be able to give all those options to customers like table extension leaf, color, etc but the measurements seems to be the hardest.



How can we do this in CS-Cart?