Outdoor Wilderness Fabrics is an excellent source of patterns and all kinds of supplies for outdoor gear. They are nice folks to deal with as well, prompt and helpful. They don't have online ordering up yet, but you can call or fax orders in. The advantage of the old Frostline kits was that they were complete: they included precut fabric, all notions, insulation, great instructions, etc. If anyone else is doing that kind of thing these days, I haven't heard about them. But if you want supplies or patterns, Seattle Fabrics (in an earlier post) and these guys (Outdoor Wilderness Fabrics) at http://www.owfinc.com/ are both good to deal with (be forewarned that OWF's website doesn't view well using Netscape. Use Explorer if you have it).