Honestly, I wouldn't suggest Border Collie. For a couple reasons. One, a Border Collie pup/young adult is going to be a HUGE change in activity level/mental stimulation needs compared to living with an older dog for a number of years. I know you said you would like to pursue sports, which is great, but I think you can find what you're looking for in a less intense dog. Two, I do worry about the ferret issue. They could be fine with a little training, or it could blow up in your face easily depending on the dog and take alot of work to over come.
I would stick with a non-herding breed, personally, since you already have the ferrets. I second the idea for a small Golden-type. They'll be an easier breed to handle, energetic, handler focused, wouldn't be as ferret obsessed, and most certainly excel at sports.