You have to be a little careful with your motors because the rated 1000 Watts of power is probably the continuous rating. The motors will have a stall current of well over the rated 27 Amps. That's why the Pololu controllers would not work. The Pololu and Adafruit boards are great, but your motors are a little big for them.
I think the scooter motor controller would have a tough time handling the current for your motors as well. Its technical specs suggest it for a 350 to 600 Watt motor, not a 1000 Watt motor like yours. (Though it does say peak current of 40 Amps, so it may work with your motors -- hard to say.)
If you can run both motors with the same controller, a golf cart controller like this one might work at a relatively cheap price: www.evdrives.com/product_p/con-spm48225.htm. That controller should be heavy duty enough to handle any current your motors pull.
But that controller does not switch directions (forward and reverse). To enable that, you would need a reversible contactor like this one: www.evdrives.com/product_p/sol-dc88s.htm.
You can easily control the above motor controller with an Arduino PWM output pin. The contactor is harder to control electronically. You would need to wire up a circuit with a transistor or relay.