Welcome to both you guys. The 7mm-08 is not a lot unlike the 7x57. I used to shoot 154 gr bullets in my 7x57's because they shot so well. But I think if I could have got the 139/140 gr bullets to shoot better, I'd have used them more.
I'd stick with whatever you are shooting now. The 7mm - 08 is plenty of rifle for antelope with any hunting bullet. Accuracy and knowing the rifle and how it shoots are far more important than anything.
Federal Premium 140 grain with Nosler Balistic Tips or Winchester Supreme with 140 grain Balistic Silvertips. Either one of these should be very accurate, give you great long range performance, and be just the right type of bullet to take down your 'lope. Have a great hunt!
Understanding wind currents and thermals in hilly, broken terrain can often be incredibly frustrating. I've found that collecting and storing milkweed seed pods during the late summer has made me a better hunter in the bluff country that I hunt. These little feather like seed dispersers will float on the lightest of air currents and will show you what the wind is not only doing right at you're location but more importantly down range. I like to use the off season to float them...