Stud worthy?

Hello! My name is Steph, I'm kind of new on the board, and I have a 18 week old chi named Sonny bear.
There are breeding questions I want to ask, probably with answers I can find in the books I have, but asking ona forum is a real-life experience view point kind of thing, you know?
Anyways...when we first got Sonny, we did not know much about the breed...Since, My boyfriend and I have fallen in love with the breed and are really starting to read up...We talked last night about possibly training ourselves and Sonny for showing...but thats a whole other story...
He is very young now, but my boyfriend wants to look into keeping him intact and possibly offering him for stud when he is older. We don't want money or anything, just pick of the litter...someone told me people get stud fees the other day, and I guess I never thought of that, I was surprised!...
There are a lot of things we need to check into with him to make sure he is a perfect example of the breed before I would want him to procreate...We are going to start looking for a new vet...since our vet doesn't seem to really be a small dog person and even called him a rat and "not really a dog" the last time we were there...
If we find a good vet, maybe one that chi breeders in the area bring their pups to, would that be best to get info about Sonny being the proper dog to breed?
I'm afraid to ask my breeding questions on the forum just in case i phrase something the wrong way and people take me for some ignorant puppy-mill back yard breeder...
I want to keep the high standards of the breed, and If i went to a reputable breeder and vet that is familiar with chis and they said Sonny was not good for stud use, then we would have him neutered and just buy our next dog..
I thought maybe you would have information to offer me about preparing your puppy for stud use, things to check for, look for, make sure he does or doesn't have...
He is not AKC registered, but he is CKC registered along with his parents and their parents, etc...So we know where he came from and all that jazz...Im waiting to receive his full pedigree from CKC...
I don't want trouble on the board...Im NOT trying to make any money, please believe me, like I said, we thought about this to possibly try to get pick of the litter only..

Anyways, if you can find my questions in that mess, i'll be impressed!
Thanks for any information you can offer me...

Also, about size...I see that it is important for the female to be at least 4.5 lbs for breeding, but what about the size of the male? Sonny is only supposed to be 3 lbs or so full grown (says the chart on here) he is barely 2 lbs now at 4.5 months...