Oops! I wrote inches where I should have written feet in several places. I even had another mechanical engineer check before I posted this and she didnt even notice it . . . I guess I was inspired by NASA
Anyway it should be corrected now.
I probably should have written this using the metric system . . . its just Im american and although it is easier I believe to calculate in metric, it is easier for me to think in the english system.
As long as you stay consistent with unit use, your RMF will always be:
Torque * rps > = Mass * Acceleration * Velocity / (2 * pi)
So I did the calculations, and I got the same motor RMF's as you:
86 lb in rps
99.4 lb in rps
And finding the minimum RMF required, I got:
(13.22lbs * 3ft/s * 2ft/s^2) / (2 * pi) = 1817.88 lb in rps
(6 * 91.44 * 60.96) / (2 * pi) = 5322.95 kg cm rps
Those motors are way below your spec . . . you might just want a velocity of 1 ft/s and accel of 1 ft/s for a minimum RMF of 303 lb in rps. Then find a motor about 3x better RMF than motor 2. The problem you will find is that stronger motors are expensive and weight on your robot means money out of your pocket . . .
Anyway let me know if I pulled a NASA again . . . g'luck!