1:34 a.m. on April 17, 2012 (EDT)
Basically, I agree with what Brerarnold and Callahan said above. I've been lucky in that the stuff I tested has actually worked out for me pretty well. That's where reviews come in, like on this site.
I read a lot about the layering techniques, lightweight equipment, etc, and then bought a few things I though fit well into a system, and have been using them ever since. I don't know if it's any use mentioning any specifics, since these will vary from person to person based on basic things like physiological differences (warm sleeper, cold sleeper, sweatier, dryer, etc) and personal preference (wool, down, synthetics, weight goals, etc).
However, it's not as daunting as it sounds. The key will be to field-test your gear on day hikes, overnights, and short outings before you decide it's a must-have on a longer trip. And even then, there can be opportunities to swap out for different stuff. For example, I hiked 164 miles of the AT two years ago, and started out with overly heavy Columbia boots. As soon as I had the opportunity, I switched to a nice pair of Montrail Sabinos and have not looked back since.
Live and learn. Everyone has their own preferences and process.
Oh, welcome to TrailSpace!
--Peter
edit: Hocking Hills is awesome, I agree! Oh, and finally, you don't always need to dish out big $$ for the "best" stuff. For example, I've been very happy with my Eureka 1-person backpacking tent. It was light, water-tight, and very easy to carry when I was on the Laurel Highlands Hiking Trail in PA, and I got it cheap at a sale at Dick's. A great price-to-features ratio, IMHO. It was initially tested at Hocking Hills.
edit2: And could you please clue us in on how you get pro deals on your gear?? Inquiring minds wanna know!