There are no complete floor pans available for the '60-'66 Chevy/GMC trucks, Panels & Suburbans, only a few sections. The cab floor front half (LMC Part #38-8974 & #38-8975) are an option, as well as outer cab floor (LMC Part #38-8982 & #38-8983), will take care of the biggest part of the floor area. These items are also available from:

www.classicparts.com
www.oldchevytrucks.com
www.bowtiebits.com
www.truckandcarshop.com