My experiences, having 2 basenjis with master versatile basenji titles, is don't count out breeders who don't have dogs titled at both ends. My Digital, the brindlewonderkid, has excelled at everything I've asked and his sire only has his Ch and his dam not even that. But he has done wonders in agility (top 3 in AKC for 7? years running; and finished up #5 in 08 where he was "competitive" for only 1/2 the year; he's since been moved to preferred), conformation (took us a little while but he did get a group win and several nice breed wins; all that with a novice handler), rally (didn't go too far due to me, but he did get his RN with 2 firsts and one second place with a high score of 99), lure coursing (got his FC in 4 runs with 2 Best in fields; ran Mother's day this weekend at 12 years old and qualified) and he's a wonderful -therapy dog (doing that tomorrow). Jet the tri-ing has also done respectable in all those areas; his biggest downfall was having Digital as a big brother. Zest, my superstar in training, is also going to excel at all of those too. She's started in conformation and coursing, and her debut in agility is in the next few months. None of these dogs come from a pedigree with performance titles. All are Jerlin dogs, and as much as I love Linda and her dogs, I just don't see her taking up agility any time in the near future. <shrug>But her dog's do seem to have potential for it; at least they do in my house.
I would suggest that the dog's temperment and health is more important than his/her pedigree. I would also tell you that there are very few basenji breeders that I would trust to assess an agility prospect. Most basenji people just don't do agility and I don't think the best LC prospect is going to always translate to the best agility prospect. My breeder, for which I'm forever grateful to, let me choose between the 2 female pups. The reason I chose Zest was she had more desire to work/interact with me. There were several things I considered, but this was the biggest consideration. And I don't know if someone else would have a different conclusion. Is what I saw something between me and this individual pup, or would she work better than the other puppy with anyone? No idea.
THE most important thing, however, is a getting a dog that fits your household. Yea, I do a bunch of stuff with my dogs, but the majoritiy of their time is spent as house pets. I think just talk to the breeders, be open and honest. Just like you did here. I'll let you in on a secret, basenji breeders are just people.
Also, why not do an agility class with your b-mix now? Mixed breeds (aka All Americans) are welcome and encouraged to do many different agility venues and it looks like the AKC will also welcome them soon. Might as well figure out if that's something you really want to do with your next dog AND you'll have lots of fun and learn lots in the journey. You may start doing it and find out you don't really want to do that (although being such an agility junkie myself, I find it hard to believe that that would happen). Many LC clubs offer fun runs; most dogs of nonsighthound origin enjoy this. By doing agility with your current dog, you will get a better idea of what you want with your next dog; you will also show you prospective breeder that you're committed to the sport and know what you're getting into. A basenji breeder may tell you that basenjis aren't really suited for agility/obedience and by showing that you already have, you will be in a better place to convince the breeder "yes they can!" Although, I think this attitude is less than it has been and I must admit that nobody ever told me that. But by the time I would have asked about that, Diggie already had agility titles.
If you have any questions, feel free to email me. If you're a BCOA member, I'm the only Kim McNeill from Colorado. And if you're not, JOIN! By all means, join.</shrug>