Ditto what Beverley said.
A really good but relatively inexpensive (was 99$ for me)whip is the “beginner bullwhip” at the “aussie saddle co”, link below. Note: there are lots of whips available at this site, so make sure you pick the right one!!! It has a pretty da*n nice crack to it for the price. If you are wanting to know more about how to crack a whip, their DVD "Whip Cracking With the Masters, vol 1 is good…explains the technique. I use mine on cattle (and the occasional cowdog). And though, technically, one is only supposed to use only the “crack” to work stock with, the occasional “pop” on the ol’ hide gets the message across better.
For fox hunting, I use a traditional hunt whip, with my own version of a popper. I also bought a nice kangaroo stockwhip for a good deal when I bought with the “beginner whip” , but it’s so nice, I hate to use it! The western tack store whips I’ve bought have not been very good at all and are the same price as the Aussie bull whip.
They also sell spare poppers, which might be worth it. Personally, I just braid up a really skinny braided popper out of bailing twine, but it takes more time to separate out the small lengths of twine than to actually braid. You can also use very narrow guage nylon cord (hollow) with a commercially available popper that is about 6" long and fairly stiff. These are available often at ranch supply stores. They are a fairly stiff popper but make for a good “business” end when you want meaning attached to the crack. Not really necessary for the average hound, but cowdogs, bulls and onery cows, yes.
Good luck!
http://www.aussiesaddle.com/shootist_whips.html