I use the extended. The SPR is more for big long scopes. I don't have that scope but I've got a couple Burris 4.5x14x42's mounted and it's kind of a compact scope but looks good. If you send me a PM with your email, I'll send you some pictures of what it looks like mounted.
I don't know if you ever looked at them, but American Defense makes some really great nice mounts made in the USA. They are a little pricey but I use the Recon Quick Detach mounts with dual detach levers & they're the best I've ever used. I keep a scope dope book of my settings & use 1 scope in an AD mount on 2 or 3 rifles. Put on rail, push forward, lock down, set to zero for that rifle, and they always go back to zero. A great way to use an expensive scope for several rifles. I can't afford a Nightforce for every rifle & this is a great option & a super great mount & they make them in different heights and several models. I still have a few Aero Precision mounts on a couple cheaper rifles with cheaper scopes but my buddy's & I have just about switched everything to American Defense mounts. Sorry for being long winded.
Jim D