Very good recommendations by people on Glocktalk. The next steps may be as follows.
1. Amazon.com has user ratings of different knives. You might pay particular attention to the negative comments. If a person looks for a knife for a particular purpose and say the knife is ok, but the sheath gets a bad review, you would want to factor in the cost of a replacement sheath. Oh yeah, I recently received a very decent knife and the restraint was a piece of velcro that was already failing right from the box. So, now the Afghan has a decent kydex sheath. Remember, Amazon will have perhaps 100 or more ratings on a knife.
2. Consider looking at youtube videos on the specific knives under consideration. You might learn that Esee knives can be purchased without a sheath and so you avoid spending the money on a factory sheath if you want something different.
3. For many people, the carry system/sheath may be critical. Yes, I know of Benchmade folders and other folders being carried in Benchmade horizontal/vertical option sheaths. Make sure that you consider the carry options and if you don't seem to find a decent carry system, ask the vendor or the manufacturer for a recommendation.