Dexter; I would recommend the Sigma 150-600 mm. You can get the Sport model, (they should really call it the "Professional" model") for around $2000 or get the Contemporary model for $1000. The difference between the two is the Sport model has a more robust build, but they both use the same lens. I have been using the Sigma for wildlife and sports for quite awhile and find it tack sharp at a very reasonable price. I use it on a crop body so the zoom is even greater than 600mm. Actually it's 960 mm when fully extended. The lens does great on a tripod but also does great handheld. I you would like to see a good review of the lens go to https://www.youtube.com/watch?v=F6tCUFXiDws

I hope you find what you are looking for.