I will admit I don't have a lot of first hand experience with the 7 mag and factory loads but I am an experienced re-loader. For deer and antelope many people tend to use the lighter, soft point bullets. This is fine, but I would recommend you stick to a bullet with controlled expansion. the velocities of the 7 mag can do a lot of unneccessary tissue damage with bullets that are not bonded or have a thick jacket. I hear a lot of good things about the hornady line of ammo and personally like their interbond and interlock bullets. You can also find factory ammo with nosler accubond or barnes bullets. In your case, probably the most important thing is accuracy and you may have to try a couple brands or bullet weights to find what shoots best. Enjoy the shooting and good luck in pursuit of the goats.
I'd go with the Winchester 150 ballistic silver tip. I've used 150 grain nosler ballistic tip hand loads and these are almost the same thing. The 150 had a thicker jacket than the 140 and bring heavier will also be slower, which helps reduce blowups and increase penetration. Also has a better bc and does better in the wind than a 140.
I've used the 150 gr Nosler Ballistic Tips on deer and pronghorns with great success and reasonable meat damage when shots are properly placed. Used the 150 gr Swift Sirocco on elk successfully too...nearly identical drop chart. Just bought a Savage Long Range Hunter in 7mm so will see what it likes best. Will try the 168 Berger as an all around load.
What does "gauge" mean anyway? As used here gauge means the number of round lead balls the same diameter as the inside of the barrel (aka the bore) that it would take to weigh one pound. It takes 12 lead balls the same diameter as a 12 gauge barrel to weigh a pound. The smaller 20 gauge would require 20 balls of that barrel diameter. The larger bore 12 gauge would require 12 lead balls of the bore diameter to weigh one pound.
In general the number of pellets in a shotgun shell...