Here's my tuned pipe setup on the .91 FX that's in my King Kobra:

Pipe: Macs P/N 1190 non-muffled

Header: Macs P/N 2981 cut down to 6". That's measured from the front of the header flange to the end of the header tube just like on the Macs website. This is the LONG header, since I needed to have the pipe away from the plane a little ways. I don't think it's the longest one they make though.

Pressure tap: right where the pipe diameter peaks.

The one you're considering should work fine, it's within the ci range they recommend. I think mine is turning somewhere in the neighborhood of 12800 with a 13x8 prop; she'll climb till I pull the power off. Hope this helps