I would still go 891...really the 921 and 923 are pretty much useable in the same situations, the 921 just uses slightly bigger sockets but what they can do is almost indistinguishable from a torque perspective.
Really though, in the end, you'll get all three (921, 891, and 900) because we all love having lots of tools here
Really though, in the end, you'll get all three (921, 891, and 900) because we all love having lots of tools here