I can't believe nobody's recommended the Spyderco-made Byrd line yet. My impression was that they had replaced the Kabar Dozier for the BFC's Favorite $20 Knife award! I don't own one, so I can't recommend them personally, but they've gotten almost universal positive feedback on the forum here. Just search for "Byrd".
(As a side note, what an insightful naming system on the part of Sal- pick a product name that will be the ONLY result if you use it as a keyword in a search. "Cold Steel", by contrast, brings in TONS of irrelevant hits.)
What I can recommend, though, is a Victorinox One-Hand Trekker. It's a little different than the folders you've been looking at. On the negative side, the blade is of a less spectacular steel, and they don't come with a pocket clip. On the plus side, though:
it's the right size,
opens one-handed,
has an almost unique serration pattern- which I happen to like quite a lot-
and, most importantly, all the extra tools you need to keep from having to abuse the blade itself.
Scrape, pry, poke holes to your heart's content... but not with the blade. THAT, in my book, is a useful knife.
$28, shipped, too (bought my last one at QVC.com)!
Mike