Labradors have a HUGE problem with hip dysplasia, what are his hip scores?
He and the bitch should have a hip score well below average, you shouldn't even be considering breeding him without getting this done.
There are other genetic tests that need doing but you will have to google them as gundogs are not "my breed".
You say he is a working lab with good credentials, what are these exactly?
Is he an outstanding working dog?
A FTCH? A proven, excellent worker?
Every dog owner has a 'just wonderful' dog, my dog is PERFECTION.
She is wonderful with kids, dogs, she has a high prey drive and I feel would like to harm my cat, yet gets on with her for no reason other than to please me.
She is beautiful, obedient, what more could you want?
But it would not be right to breed her.
What would she add?
Nothing really, just more collie pups to an already saturated market.
You need to have an outstanding reason to breed, especially a breed as popular as a lab.
It doesn't sound like he is registered nor from health tested parents.
If he was, his breeder would be willing to mentor you and give you all the help you need.
Unless he is an outstanding, proven worker and health tested (I mean expensive hip x rays, blood tests for genetic disorders NOT a vet check) you are HIGHLY unlikely to be able to find a good quality bitch for him.
What you will get are the dregs, poor conformation, poor working ability, possibly poor temperament bitches whose owners have no idea and want to breed just for the cash or the experience.
Studding a dog can change their personality, for the worse.
You also have I ask yourself what happens to the pups.
As the stud owner, you don't have so much control over what happens to his puppies, what sort of homes are they going to end up in?
The sort of bitches you are likely to get are unlikely to produce desirable puppies i.e. Temperament is largely inherited, a nervous or aggressive bitch will likely produce pups who mature the same, without both parents being proven workers they won't be desirable for working homes, as he is unregistered and working type show homes are out, that leaves you with the pet market.
You are spoilt for choice if you want a pet lab, they are ridiculously popular already.