We're allowed to post breeder/kennel names here, right? I'm in several communities where it's not allowed, but I think I've seen other people do it here... If I was in NY, I'd probably contact the following US-based breeders:
WYSIWYG Home of Champions - Blue/Black - They have beautiful dogs, do CGC and sports as was as conformation events with them.
Von Charm Great Danes, Kennel, Fawn, Brindle, Member Great Dane Club of America, soundness of mind and body, substance, movement, type, size, and elegance. - Fawn/Brindle - Gorgeous dogs, many have CGCs. Or the following Canadian breeders:
Cupar Farms - HOME - Blue/Black/Fawn/Brindle - Lovely dogs. Have a litter expected next month if you're in that much of a hurry
Dantry Danes - Blue/Black - They are on my short list of breeders for my nextdog. If you want a harlequin or mantle, you're going to have to drive 6+ hours one way or fly one in, it looks like. No harle breeders registered with the GDCA or GDCC are within a reasonable distance of you. I'm also not sure what your budget is, but just to warn you, don't be shocked if puppies from those four breeders are $2-3K. It costs a lot of money to show a dog to a championship, to properly health test (PennHip, CERF Eyes, OFA cardiac exam) and to raise a litter. Good breeders LOSE money on litters. They breed because they love the breed and want to improve it, not to make a profit. A few other thoughts: About a rescue dog - I've found that rescue Danes are usually backyard bred dogs. It's just a reality that you're most likely not going to get the kind of lifespan out of a rescue that you would out of a puppy from a reputable breeder. You're also most likely going to face large vet bills because of the poor breeding. But there are a lot of rescue Danes out there who need homes. I've also experienced difficulties working with rescues, as most of them have very intense requirements, such as you can't leave the dog at home for longer than 6 hours at a time, you have to have a fenced in yard, etc. If you meet their requirements and can find a breed specific rescue in your area, then go for it!