Even though you can put an exhaust brake on your tractor doesn't make it a good idea. We hauled a 5,000 gallon liquid slurry tanker with our Allis 8550 and used the engine from much of our braking (no engine brake). After a couple of years the transmission was shot and we had to replace almost every gear due to wear. Everything in the drivetrain is designed to be loaded almost exclusively to propel the tractor, not provide extended braking. Not to say you can't get away with it, but don't be surprised when something breaks.
I thought about electric trailer brakes but I have no experience with them.
Air compressors, air brakes and pintle hitches are offered on European versions of tractors as they tend to haul with them much more than in North America. I believe this started after WWII when the GI's left quite a few large trailers behind because they weren't worth shipping back. Given the popularity of Fords in Europe you should be able to find the parts to equip your tractor with a factory designed air brake system, but will probably be expensive when you consider VAT and shipping.
ISZ