Agility trials, Border Collie or a Munsterlander (English Spaniel). The English Spaniel and Munsterlander look almost identical, the difference is in the temperament. Munsterlanders are almost universally lovers and really affectionate, eager to please. The down side is they are sensitive and don't do well with harsh commands, you have to coax them with kindness.

Vislas are popular now and with most popular breeds many breeders are in it for the bucks. It may look like a Visla, but may act like a neurotic idiot.

Want a bigger dog think about a Weimaraner. They also come in flavors, mine was a good family dog, a good watch dog, an excellent gun dog, but a poor retriever. He was breed for his nose, his kin were scent trial champions. He had some of the temperament of a hound, but changed gears as soon as the rifle came out of the gun cabinet. I've seen him follow a blood trail at a full run with maybe one tiny drop of blood every 20-25 yards or so, his nose was unbelievable. I had a pair of Weimaraners that were born bird dogs, they would point and flush. I never had to train them a bit. What I'm saying is it may be the same breed, but different lines have different dominant talents.

The best trials dog I ever had was a Boxer, Shepard mix, Boxer dominant in looks but with a longer snout. There was nothing I couldn't teach her that she wouldn't learn as long as I was able to communicate my wishes to her. She was nearly as fast as a speed dog, but could run forever. She had a lot of bottom and just kept on going. She'd run Yotes until they collapsed. She was eye dominant and what the English would call a lurcher. She was whistle trained and seemed able to anticipate what I was after, an outstanding stock dog. Sometimes you just get lucky. She was a sure enough Frisby freak and really acrobatic. Best all around dog I ever had the privilege to bond with.