Zen Cart Mod Product atrribute Quantity Box

This is a repost of the zen cart project I need someone to implement something exactly like this: [login to view URL],3345 for Zen Cart. Maybe just replace the current "text box" attribute option with a quantity box. The quantity entered by purchaser needs to be reflected in weights and prices during checkout and needs to work with downloadable products. Someone who knows Zen Cart and PHP should be able to add this functionality fairly quickly. (This is similar to work oscexpert appears to have done for proxykitten in May 2007 and momleetech for craigkendall on 12/2007.)