The whole Fiplex Honeywell thing is a mess I'll leave uncommented on, we've always done our designs in house for that reason... Anyways, for us we have electrical pop a 2" pipe out the roof with a weatherhead. Ignore the 2nd pipe, electrical got excited there. Depending on where you need to point the donor antenna will determine what height you need, it's recommended to be 24" over any obstruction. You can strap some unastrut to the 2" pipe and use that to support your antenna if you need to get higher or you can just use a pipe bracket to mount the antenna right on the pipe like we did. The polyphaser (that in-line lightning protection) can go right up on the roof and then grounded to building steel.

Mind you I just do the drawings so my field installation knowledge is a little less, but yeah this is mainly stuff they don't include in any details.