Well, i hope things work out whatever you decide to do. I tend to agree with the above post, it will only confuse the pup more to go for a "trial" with you that doesnt work out then be sent on somewhere else… I think you really need to give it some thought.
And just as an interesting addition, its not just basenjis that are like this! My two female pugs (not littersisters) cannot be in the same room as each other. They cant even be crated together. You wouldnt think pugs could do much damage but having been accidentally bitten whilst trying to split them up i can assure you they do - they drew blood and half my hand was very badly bruised! It got so bad that one now has to live with my mum. And these two were inseperable as pups, the best of friends! Until the youngest got to about 18 months. And they are both very friendly with other dogs, its just each other they dont like..
So, even if you did do the trial and all went well, theres no saying that in a few months time you wont have problems.