Agreed, this same post seems to pop up from time to time, I think this last time, we kinda nailed down that its all the same stuff basically, and to shop for price. I personally like to shop LMC for their cheaper priced stuff (you gotta watch them though because some of their stuff is priced very low and competitively, while other stuff is way overpriced) For most of my other needs I generally use Jim Carter, they have friendly staff and their shipping rates are real fair. They sometimes have issues getting things to you timely, but I guess thats a never ending battle between the consumer and the supplier no matter what line of business you are in. Ive never used Classic Parts, but I hear lots of good things about them.

1950 Chevy 3100 5 window "in progress"
1967 Chevelle 300