In past I have used Rockland Immunochemicals in Limerick PA. They were good and offer your service. Best to find one local CRO nearby to you. Some animal facilities will do it within your institute if you set up an animal user document.

I have used several companies for mAb and pAb generation.  

first some general items:

Develop a plan with any of the vendors regarding conjugation of immunogen or not, adjuvant choice (or at least confirm the one they use is OK), and the number of rabbits to start with (in case you don't get sero-conversion).  I would also spend the extra time to outline a screening strategy and possibly even provide them the assays to perform the screening.  These results can then allow you to make a choice of whether or not to stop a single rabbit, continue, boosting schedule, and timing on when you will terminate the program and collect terminal bleeds (if at all).

Green Mountain antibodies

https://greenmoab.com/

• Average turn around, big shop, so you may not get the personalized experience you are looking for. 
• One advantage is they have work with some of the bigger companies and should be able to help you out with some general questions.

Antibody Solutions

http://antibody.com/

• smaller company, but you will get more personalized service.  The primary contact here is one of the authors on the white paper on critical reagent generation and life cycle management (John Kenney)

B2S Labs

https://b2slabs.com/custom-reagents

• Another smaller company with great expertise in generation of custom reagents.  This is a company that Dr. Ron Bowsher has built, and it comes with his expertise in reagent generation and ligand binding uses.