Get one that has a 1.5” optical centerline height and 20 MOA cant. It’s up to you if you want the QD or traditional fastener version. One such example is SP4602, which uses traditional fasteners to mount to the receiver rail.
You may want a cantilever style mount for proper eye relief however, which spuhr also makes, SP-4616. Same height and downward cant.
For precision oriented large frame ARs I prefer traditional fasteners over QD style. I have the SB 4-16x42 on my Mk11 and it’s a perfect match for it...I use a KAC mount but the Spuhr is a great choice as well.