What would I need to do to get my Donkeys able to breed?

I have recently noticed that one of my 3 stallion donkeys has started watching the mare horses my neighbor owns across the street and he has started making that donkey noise to them, whenever they are being ridden on the road next to the pasture he goes CRAZY!! I am wanting to set them up to start breeding with other donkeys and possibly horses, I was wondering if I would need to register them in order to make them eligible to breed or if I would just have to get a vet to check them out! They arent broken to ride and only one of them is halter broke but he doesnt take the lead very well and the other 2 havent been halter OR lead trained! I am willing to break them to go with a halter and lead if its is needed to transport them somewhere to breed, I will spend UP TO $200 for all 3 to get vet checked but if I have to register them and it costs more then $300 for all 3 of them then I just wont breed! The donkeys are in a WELL over 100 acre pasture and they are VERY used to cows since they are put in a 50+ cow pasture! The only skiddish donkey is the second largest, the biggest donkey is VERY bossy around the others and the smallest is the nicest of the bunch! I just need to know what all I would need to do to put them up for stud? We have a little pen we can use for a breeding pen so we wouldnt need many supplies, we just want to give our donkeys a chance to be daddy's for once! Thanks for the comments and God Bless You All!