Charles,
I am sorry about the loss of your dog. Are you looking for another yellow, or possibly a chocolate or black? How far are you looking to travel? What type of lines are you looking for?
If you visit these websites you can do a breeder search by state. Its a decent place to start, as most breeders who list with the clubs seem fairly reputable.
www.nationallabradorretrieverclub.com
www.thelabradorclub.com
http://www.working-retriever.com/home.html (has links to a bunch of breeders around the country - good retriever site)
I spent a few months last year looking for a breeder myself on the east coast, and here are a few that I bookmarked. I have no affiliation with any of these breeders, they are just some that I were considering:
http://wassookeagretrievers.com/ (Maine)
http://yorktonkennels.com/Welcome.htm (PEI)
http://www.pioneer-retriever-kennel.com/index_home.htm (Virginia)
http://www.partridgehill.com/index.htm (Massachusetts)
http://www.rebelridgefarms.com/retrievers.htm (Maryland)
http://www.vanlee-labradors.com/index.htm (New York)
http://www.peakperformancetraining.info/ (New York)
http://www.morningsunretrievers.us/Home.html (Virginia)
http://www.rhumblineretrievers.com/index.html (New York)
http://www.diamondbrook.com/index.html (Vermont)
I hope this helps. Its a big world out there when searching for a puppy, but its a fun process. One of the best ways to ease the pain of losing your dog, is to get another.
Let me know if I can do anything else to help,
Neil