Forget the FFP, SFP is better 95% off the time for this application. I wouldn't go over 18-20 power as your field of view will do compromised you will struggle to find the elk in scope and lose it at shot.
You can go to 500 yards with just a hold over style reticle but turrets will certainty work. .
There are so many great options for this that it boils down to what your budget is and what feels good to you. 30mm scope is a great call as many of the good scopes for this application are of the 30mm variety.
A good quality 3-15 will work. A 4-20 will work great too. When you get to 20x magnification you will want a better quality scope or this no point in having all that magnification
