Mack51

I have a Singer 168w 101, a post machine. I am teaching myself to sew and right now I have a clutch motor and want to change to a servo. There seems to be few to choose from and having looked on e bay also. I have a budget of 200, I am retired. Need help in picking out one, any ideas. Currently I am leaning on one on e bay from S.E.W. for 139.00 and it has the S.E.W. label on the motor. Looks the same as a Reliable. John