Almost any major tire store will stock them.
If you're looking for a history on whitewall tires, Wikipedia has a great article on it: http://en.wikipedia.org/wiki/Whitewall_tire Should you be looking for more info on purchasing them, try the Universal Vintage Tire Company. They have a wide selection of whitewalls for you to choose from: https://www.universaltire.com/american-classic-tires.html
A 2015 Chrysler Town & Country is 78.7 inches wide.
The 2013 Toyota Land-Cruiser is 6 ft. 5.6 in. (77.6 in.)1 subwoofer(s) wide.
The 2002 Toyota Land-Cruiser is 6 ft. 4.4 in. (76.4 in.)1 subwoofer(s) wide.
The 2005 Toyota Land-Cruiser is 6 ft. 4.4 in. (76.4 in.)1 subwoofer(s) wide.
The 2014 Toyota Land-Cruiser is 6 ft. 5.6 in. (77.6 in.)1 subwoofer(s) wide.
The 2011 Toyota Land-Cruiser is 6 ft. 5.6 in. (77.6 in.)1 subwoofer(s) wide.
The 2004 Toyota Land-Cruiser is 6 ft. 4.4 in. (76.4 in.)1 subwoofer(s) wide.
The 2003 Toyota Land-Cruiser is 6 ft. 4.4 in. (76.4 in.)1 subwoofer(s) wide.
The 2006 Toyota Land-Cruiser is 6 ft. 4.4 in. (76.4 in.)1 subwoofer(s) wide.
The 2007 Toyota Land-Cruiser is 6 ft. 4.4 in. (76.4 in.)1 subwoofer(s) wide.
The 2001 Toyota Land-Cruiser is 6 ft. 4.4 in. (76.4 in.)10 -way power driver seat wide.