For installs, I prefer doing either the ARH or the Stainless Works.
Both have their advantages and disadvantages. I like the bolts that come with the ARH, and the bolt holes are slotted both top and bottom, where the SW are only slotted on the bottom, making the passenger side a little more difficult.
The SW have a break in the flange on the drivers side so the dipstick doesnt have to be removed completely.
The ARH comes with O2 extension harness, the SW does not. The SW are a little cheaper, but I feel the quality is about the same.
If you are going to do the install yourself, I very strongly recommend doing it on a lift, and have 3 pole jacks and an extra person to help you remove the K frame. Having the K frame out makes the job about 300% easier.
If you give Fred at Evolution a call on Monday, he can hook you up on a good price.