Add to that, "and what looks about right."

There are really only about 5 classes of servos in common use:
Pico (HS-50)
Naro (HS-55, HS-60)
Micro (HS-81, HS-85)
Mini (HS-225)
Standard (HS-425)

...and there's quite a bit of crossover where at least two different classes of servos would work equally well. It's really hard to go wrong.