I need a small quantity of the white reflecto sheeting, is there a place to buy it.
I've purchased some small sections (short rolls) off of eBay. Otherwise, check with a few sign manufacturers -- they may be willing to sell you (or give you) some scraps. If your needs are small enough, you might be able to contact Avery or 3M for some samples. Depending on the type of sheeting and size you're looking for, many hardware stores sell reflective tape in various colors, basically the equivalent of Engineer Grade sign sheeting.
Thank you, what exactly should I search for on ebay, the prismatic type? I want to make a fak logo that would go on a "Adopt a highway" sign.
Depends on what spec's you're trying to emulate. Here's FHWA's sheeting guide (http://safety.fhwa.dot.gov/roadway_dept/night_visib/sign_visib/sheetguide/) as a reference.
It's for an "Adopt a Highway" sign on an interstate.