I have Kenetrek boots that I have worn for a few years and they have been exceptionally comfortable and stable for my feet. However, I think they would be a bit much for an antelope hunt since even the Uninsulated models run hot and as mentioned they are very stiff in the sole.I've been antelope hunting in Wyo since I was a kid growing up. My preference...especially for antelope is mid height/weight hikers. I live in Colo and work year-round outdoors and have never seen the need for insulated boots. Mid weight hikers are a chunk lighter weight than tall boots and will be a little cooler. I hunt sheep and mtn goats as often as I can and a quality mid height/weight hiking boot has plenty of support for the roughest terrain.
Although it can be warm and even hot antelope hunting my preference is all leather boots. The fewer stitching the longer boots will last. Most boots with synthetics I've warn often come apart at the seams when wet. Depending upon what state you are hunting you may have lots of cactus. All leather will likely protect your feet from spines. Unfortunately all leather is a tad heavier weight than synthetics and may also not breath quite as well.
I know I may upset a few guys but I wore Kennetrek's one day and returned them. It felt like I was on stilts and super unstable with the thick, tall soles. I literally stumbled all over the place on steep, rocky hillsides. You will also find it nearly impossible to stalk quietly with stiff, tall, thick soled boots.
If you want the cream of the crop I'd look into Crispi's and possibly Lowa's. Crispi has a large selection of boots. If you do a search they usually get rave reviews. They aren't cheap but you usually get what you pay for. I don't skimp on footwear...it is that important to me! If you do a web search you can find older Crispi models that are currently around $100 off. I've also had good luck with several pairs of Lowas but have slowly switched over to Crispis.
I would recommend buying 1 size larger. That way you can trash the cheap insoles that come with the boot and also have the option of loosening the laces to add a little thicker socks for when it's cold. I also wear different thickness of socks with padding in the soles.
I too am headed out for antelope in august and just purchased a new pair of boots for that purpose. This time I went with the Crispi Colorado. They are lighter than my Kenetreks since they are not as high and not all leather so it should be not as hot. if you go the Crispi route though make sure you understand about the sole stiffness because their boots are rated in different stiffnesses based on intended use and customer preference. The Colorado is a 4 out of 5 rating, but I like the additional stiffness, which is about like the Kenetrek. Good luck on your hunt.