He hasn't even logged in for over 2+ years so I doubt he will see your post. I wouldn't mind seeing your build if you decide to take and share some pictures on here though.
Not that this will be any help, but I did multiple builds in a 2007 Tahoe. Not that any of it was great but if you want to sift through the old threads for ideas I will share a couple links below. Thanks.
I have a 14' Silverado with Bose stereo so did you do integration or add a Head Unit some where? What did you do to have it completely separate? Thanks.
PM if need be, not trying to thread hijack.
The D4800 is the direct replacement for my 2007 Tahoe so it's the same dimensions with the same terminals as factory. The fit is no different than OEM. Steve's might be the same since he used the 4800 as well