I would recommend hoping around the regular forums a bit. Most of the places you just listed have threads outside of the noob section. Do your own research there and make an informed decision, or post this in the regular forum. The Newbie section is not a good place for finding the best info.

My personal recommendation is go the the Group buy section under Mining -> Hardware -> Group buy.

If you choose the right person you can own a slice of an actual machine for cheaper than most of these sites, and you have a person you can talk with who will be managing the hardware. It's more personal and you will learn way more about the hardware itself.

If you don't like that, you are probably better off buying some mining stocks.

That is my 2 satoshi's