I can't comment on the dependability of the Flame King as we have never carried their products. It may work just fine. I think Flame King as been making grills for some time and doing a pretty good job.
This is the one we carry and have had very little if any problems with - Auto Change-over Gas Regulator
We will send the self tapping screws that attach the regulator to the bracket. If you use screws that are not the right size and strip the holes that hold the regulator to the braket, it can be a real hassel.
We do have the hoses that WILL
fit on this automatic switchover regulator and does not need any thread seal tape or dope. It is the flaired brass self-sealing type. The length will be more than adequate to interface from the regulator and the gas bottles. See Gas Hose w/Flair End
There is no comparison between the "old brass and wrench" vs the "new hand tighten style". The new "new hand tighten style" is so much nicer that is is well worth the extra money you have to spend if you have to change/replace your automatic switchover regulator or change your valves.
If you go to states that require the new style OPD (Overfill Protection Device) and have Aluminum tanks you most likely will want to change your valves. I have heard of people going on outings and refused gas because they did not have the right valves. Buying new gas tanks on your outing can be expensive. See 30 lb OPD Valve for Aluminum bottles
There is a differance between regular steel tank OPD valves and the Aluminum OPD valves. The steel tank valves will not work in the Aluminum bottles.
The companies that do pressure checks on gas bottles have the tool to put the new valves into the bottles. More than likely, they do not have the valves that go into the Aluminum tanks.
New tanks have to be inspected every 12 years and old tanks with new OPD valves have to be inspected every 5 years. If you have steel tanks it is best buy them locally, but if you have Aluminum tanks it is worth the extra effort to get the new valves.