porting 960 grid system to another website

How would I copy my customized 960 css to another website? I just want the look of my website on a different domain, without any backend functionality just the 'frame'.

Simply copy over the modified CSS files. Unless you mean the grids/blocks, then you can Export the Locations and Import the Locations on the new store.

what would be the easiest method of copying the look of the front of my store to another basic html page without and php?

You'd want to copy styles.css and any additional CSS files you've edited in your custom CS Cart skin to your HTML page, link in the copied CSS files to your HTML document, and then start removing any unnecessary CSS classes from the CSS documents until you just have what you need left over.