
I'm afraid you've left it far too late for this season, but if you start making enquiries and getting copies of stud pedigrees now you should have found a good one for next season.
Your best bet is to contact her breeder for advice on which bloodlines would be the most suitable and which would be a disaster.
I'm assuming, of course, that she's been screened clear of any breed-relevant hereditary conditions (with certificates to prove it), and you'll need to see the same evidence about any potential stud.
:)