Chris,
Rich Anderson owns Shell Valley. I have had the pleasure of hanging out with him at the Knotts show a couple of years ago, great guy. He also owns Midstates and they share the same facility with Shell Valley. Because I own a Midstates, I have met and talked with most of these guys. Their family of workers has never failed to answer a question or give advise when I needed it. If at all possible, you should visit the shops you have narrowed down as your kit supplier. You might give Bob Kallio, with Midstates, a call as well. He's part of the same family. Ask as many questions as possible. Good luck with your build!
Chris,
slithering