I think you are too late this yr to get a brindle as there were not a lot of them born this season and they were all reserved well in advance. There are still some breeders with red and white and black and whites available, the www.basenji.org is a good place to start. Most people reserve a yr in advance for a puppy.
Unfortuntely puppy mills do have a lot of brindles, but you don't want to go there for so many health and temperment issues. You might consider going to some of the LGRA events in your area, there are a ton of basenjis running in Frenchtown and Ringoes, they can point you in the direction of people planning litters who might possibly have brindles, but they are not all that common in your area.