I agree with Whittierider on all that. Wal Mart here sells two types of glueless patches for bicycle tubes. As for one kind I bought and tried to use---well, what can I say? Wal Mart ought to be sued for selling completely useless garbage. I have not used their other brand of glueless patch, and I will not either.
You do not want to be caught out in the middle of nowhere patching an innertube with patches that are completely bogus. The round or square rubber patches used with rubber glue work just fine. Do not trust Wal Mart for much at all when it come to long distance cycling. Their selection for cycling is really low grade, and very limited.
I went into department stores in west Germany, and checked out their bicycling sections. One such store was named Le Clerk. I think I got the spelling right on that name. They had just about everything you could possibly need, and it was high quality equipment too, no junk. From adjuster screws for saddles to wheels, frames, nuts and bolts, and complete bikes, they were set up complete just like a professional bicycle store. Wal Mart, Target, and Sears are a very far cry from that.
Know your tentative route. The internet can tell you if there are bicycle shops in certain towns. You can call ahead. Keep ready with spares of what will need to be replaced.