RE: .243 or 7mm-08?
If you consider yourself a GOOD shot and handload, you could be easily well served with the .243 and have the advantage of a dual purpose gun.
While I don't own a 7mm/08 I have owned a 7 X 57 and a .243 for years.
A few years ago I decided to stop carrying my .243 when I was specifically hunting a large animal. But in reality, with some of the premium bullets now available, a handloaded .243 placed well will take even large deer and will work on your sheep.
The 7mm/08 will have an advantage over the .243 ballistically.
I guess I'd tell you to get the 7mm/08 if you were going to buy just 1 more rifle.
They are both excellent rounds.