I agree this circuit is not for Power Mosfets.
Actually I am using the common TT Geared Motors off of Ebay for $1.50.
Runs at about 150-180mA. Seems to work great.
I found a slight adjustment to the circuit to allow the Arduino with 4V High to drive the circuit using a 9V Battery.
Just tested it tonight.
Arduino and circuit seems to be rotating the Motor at about 1x per Second - with good torque.
I will try driving PWM out tomorrow.
The previously suggested circuit would also solve this problem, I think.