If you know of someone with a mig welder, just grind notches in the pipe you want to use for your gate and custom make your own, or have it made.  It's not rocket science. 

Or ... if you want a custom gate that looks 'right', ...

... find a racecar shop in your area, they can bend the top and ends in one piece and notch the rest of the pipes to make it look like factory made.    Lots of dirt car racers in IA, and they all know where to get pipe bent. 

I used to race and had my own pipe bender.  Could, and did make lots of things for myself and the guys in the surrounding area.  Got burnt out on racing and got rid of everything except the mig welder that was associated with racing.  From time to time it would be nice to have the pipe bender back, but was afraid of the temptation of building another car if I had kept it.