For hunting ? I feel the Leopold VXIII 4.5 - 14 X 40mm LR part # 55265. Cost about $527.00, comes with their "Boone & Crocket" Ballistic Aiming System. It has reticle holds for 200, 300, 400, 450, 500 yard distances and can be set up for longer distance ranges, and a side parallax adjustment. Pretty cool and quick to adjust for yardage. Check out the Leupold web site under resources and click on their Ballistic Aiming Syatem training video. You'll see what I mean. I just bought one for a hunt I'm going on later this year for Elk. Also lends itself well for target shooting to about 600 yards and shorter distances down to 200 yards. It's just a thought.
I really like the leupold one piece base, rock solid and proven. You need to have gunsmith drill and tap for it, so if your worried about collector value I wouldn't. but if your Mauser has been "Bubba-ized" go for it.
For scopes I love leupolds vx-III's.
If your looking for a reliable something cheaper, Ive had good luck with Swift's.
Size & magnification would depend on your application.