I'd take the 5.5x16.5 for two reasons.
First I'd rather have the magnification and not need it than the other way around.
Second it costs less, more money for booolets.
As for the 5.5x16.5 only having 40 moa of adjustment, wouldn't sweat it, just mount it in a set of Burris Sig. rings. With the inserts you can put in what you need.
The side focus is a nice feature, however when shooting out there a ways you usually have time to adjust either one.