Well, of those four brands, I've only actually bought Spyderco, so I'll comment on them.
I'm not sure what you're looking for, but some things to keep in mind with the Civilian especially, but all those spydercos you mentioned--they look evil! You could probably get away with EDCing the harpy, but man, the chinook and civilian are really menacing and huge.
You might have posted it, but Cold Steel makes a Civilian-esque knife (some say clone) you might check out.
The Chinook is my favorite of those Spydercos. It's beefy, it has G10, it has S30V, and it looks great.
Okay, I'm just going to assume you aren't yet familiar with the steel chart.
I think it's fair to say that most people believe that S30V is near or at the top of blade steel in folders. I personally have never used it, but there are so many fans I have little reason to doubt it. The other knives use VG10, which probably has a slightly smaller fan base than S30V, but it's very popular, and I can personally vouch for its effectiveness. Very well rounded characteristics.
You really can't go wrong with Spyderco. I would really recommend that you check out their knives before you buy them though, as I've had some quality control issues with them, but if you do get a defect, they'll fix or replace under warranty, so it really isn't that big of a deal.
By the way, if you are going to order your knives, order them from Newgraham.com . They are the cheapest and fastest store out there. If you DO get a defect on a knife ordered from Newgraham, they'll let you send it back in for a replacement (which is usually faster than sending it in to be fast) or trade it in. Plus, they send bandaids with every order!
Anyway, check out some of my favorite Spydercos when you have some free time:
paramilitary
persion
native
centofante
spyderench
spyderfly