Depends on what you want. If you want 17" horns, you will need to find an area that historically produces large horns and which is not over hunted. Once you identify this unit you can go to the back of the line with all the other trophy hunters who figured this out before you and wait a good number of years to draw a permit. Plan to be ready to lay out big bucks to hunt the land where these big horns will be found, as the outfitters have figured this out before you and have leased up the best hunting grounds: you will need to pay the outfitters to hunt these prime areas. That is my take on the "hunting for big horns" game in Wyoming, and probably in most places.

If you just want a fun pronghorn hunt and don't want to wait a bunch of years to get drawn, look at unit 23: lots of pronghorn and about 100% chance of drawing. There are other suitable units as well. Look at the individual probabilities of being drawn for pronghorn which can be found, I believe, by navigating through the Wyoming Department of Fish and Game web page. But don't look for impressively large horns in unit 23 or the other units with high probability of drawing.