Major_Payne - 9:10 pm on Sep 21, 2010 (gmt 0)
I would try to design the page to the minimum browser window size expected to be used and go from there.
Choosing Dimensions for Your Web Page Layout:
How to create flexible sites quickly using standards like CSS and XHTML: [ibm.com...]
In Search of the Holy Grail: [alistapart.com...]
Care With Font Size: [w3.org...]
Most people do not like to have to scroll horizontally and there are so many better tools than mootools to have images scroll left/right. Properly done, you would have to use the extra coding to fix content to scroll function.