G'day Aus,
Haven't seen your name before so, Welcome to the forum.
The 308 is a versatile calibre as you probably know but scopes .............................not so much IMO.
That is, your requirements are a mixture and if you are hunting at close range, you need low power to give you field of view. My scope is a 1.5-5X and was very good for pigs where the longest shot was 100 yards. For target shooting, it is just about, "The sky is the Limit", where magnification is concerned. I used a 36X when I shot Fullbore and it had a Very Fine crosshair, whereas my pig scope had a coarse duplex that you could not miss at midnight
So, to sum it up, there is the reticle and magnification to be considered, for the range you shoot at.
With that Leupold that you mention, I think that you will be handicapped under 50 yards and over 300 but what is the harm in trying it out to see if you like it?
That Lithgow sounds like a nice rifle. The velocity you get out of that length of barrel should be good for 800 yards; you need about 2850 fps with a 155 gn Sierra Palma bullet for good elevation at 1000.
Anyway, you might have to think some more about your requirements. I know you want an "All-round" outfit but it's a bit difficult and you might have to compromise.
Good Luck