Unless you buy a salvage grill like mcfarmall did, you won't have to do anything to the orifices on the burners. These small grills are all designed to run on 11"WC and all of the regulators are going to reduce it down to that. You can simply remove the regulator and replace it with the male QC fitting. I say male because it's easier to manipulate the QC coupling if it's on the hose instead of the grill, but it's really your choice. I think on my Baby Q, the regulator threads were 1/8" NPT and I had to adapt it to the 1/4" threads on the QC male piece. I would recommend against using flex hose to run the line from the low pressure connection to the side of the trailer because of movement and chaffing while the trailer is in motion. I ran copper tubing and secured it to the frame with pipe clamps and had no issues with vibration, plus, you can cut it to the exact length you need and not have to deal with coiling up excess hose. I didn't use any other type of bracket or hanger, but it wouldn't be big deal to fabricate one from sheet metal if yo thought you really needed it. I didn't. You could even fabricate the entire thing out of black pipe if you had the tools to do it, that's what the gas manifold pipe is made of.
The only grills tha I can think of where you might have an issue is the Coleman Road Trip. I havn't looked at one, but I've read that they use proprietary threads and it's tough to match fittings.
2013 F250 XLT
I now have a Keystone Outback, but I try to help when I can.
Bitter Gun Owner