Magento Dependent Custom Options extension has grouped options same as configurable product. It offers comprehensive one-stop shop experience where you can calculate price based on width, length, and size with related units.
To get it now: http://bit.ly/1ghEVvn
2. Advance Magento
Dependent Custom Options
allows you to build multiple
Custom Options of a
product and make it
possible to calculate CSV
pricing based on
length, width, height and
measurements units.
4. Magento Dependent Product Options
extension provides CSV based customize
product options on the product page and
allows you to calculate prices according to
the length, width and height with
measurements units.