My dogs like these three treat dispensing toys we have:
https://smile.amazon.com/gp/product/B003ALMW0M
I have the IQ Ball, Dog Twister, and the Kong Wobbler. After you teach your dog how the toys works, he'll most likely "solve" them at their hardest settings in about 5-8 minutes. But my dog still gets all of her food through puzzle toys.
Frozen kongs filled with wet dog food are great though. They'll keep my dog busy for about 30 minutes.
My poms favourite two toys are his Kong Wobbler and this plush skinny rhino which is slightly longer than his own body length (not a puzzle toy though)
While the Wobbler used to take him around 10 minutes or so to complete to start off with, he now can get all of the rewards out in around a minute now which is a bit disappointing but also impressive.
I switched him onto this puzzle toywhich he figured out in around 15 minutes and now whenever I get it out he knows how to complete it instantly.
I need to find harder and more rewarding puzzles for my smart little guy, the potato chip bag looks interesting so I will give that a look.
Congrats on the upcoming border collie adoption! My husband and I adopted a border collie mix puppy in August and are having a blast with him. Though we still have a lot to learn ourselves as he grows up (looking forward to reading more responses here!), here's what's worked well for us so far:
We borrowed the book 101 Dog Tricks from our library. It rocks! It has a wide selection of tricks in a variety of difficulty levels and lots of helpful pictures and tips. Definitely take a look at it since you're eager to do fun tricks with your future dog.
Echoing the support for Kongs: we've been putting a (slightly wetted) portion of a meal in his Puppy Kong, layering with some flat jerky to block the top, (these treats are really high priority for our dog!), freezing it, and giving it to him in his crate after play/walk time or if we need to step out for a few hours. It's a little more challenging for him than simply stuffing it with completely loose treats. A friend also gave us a Kong Wobbler, and we use that for the majority of his kibble meal times. He seems to enjoy working for his food with it.
For chill out-of-crate times in the late evening, sometimes we give ours Bully Sticks to chew on.
These are my go-to toys: Kong Wobbler, Buster Food Cube, Kong Extreme, and West Paw Design Tux.
Hope you find some toys that fit your pit!