You're in good hands with the specifics, but will say two things:

1) I've had a Rich Johnson mount in my conversion for 10~ years, and am very happy with it. The factory setup wasn't available back then, iirc. Both seem viable—I am less excited about mounts that put all that weight on two horizontal bolts.

2) 2.2 is a great engine for a narrow 914, or any 914 for that matter. I've got 911E Ps&Cs with a bit more compression, some head work, Solex cams, and headers, and a sport muffler. While it's very nice and tractable, feeling almost more 3.0 than 2.2, next time will be 2.2S. Love those top-end theatrics, as I learned after driving another 914 with a 2.2S MFI.

Have fun, and thanks for posting. I've picked up a couple of things I might revisit!