The fittings are all low pressure Sturgis style 250 units. Most of the fittings that CW and other places sell are for the Mr. Heater units and they are not interchangeable, even though they look alike, at first glance. In fact there are many "quick connect" pieces that are "look alike", but, are meant for different purposes; air, high pressure LP, low pressure NG, high pressure NG, etc. and they are all slightly different so that you can't mistakenly use the wrong fittings together (explosive leaks can result).
I've done many LP mods to grills and even Campfire-in-a-Can units and I get all of my low pressure LP fittings from here:
Calore Equipment
This is the mod I made to my Weber Q120:
I also modified some regulators so that if I want to, I can still use the grill with a tank; in fact I modified 2 regulators so that I can not only use the little 1 lb tanks it was intended for, I can use a 20 lb tank (handy for use at the sticks and bricks when I need more grilling space for parties).
All of it done with pieces from Calore, including my collection of hoses. Even made up a quick connect "T" so that I can run the grill and my Campfire-in-a-Can at the same time. To be sure, you want to use yellow gas tape and not the white water tape to seal the threads. If you use a paste compound, again, make sure that it is rated for gas use and not just water.