Don't connect the two commons, just treat as bipolar and use the 754410 as two H-bridges. Since
the motor is 7V and the 754410 loses a few volts you ideally want a 10V supply well capable of
the maximum current (which depends on whether you use both windings at once or not).
That web pages tells you how to treat the motor as bipolar if you read it...
If the motor is rated for 1A with one winding driven, you should derate that to 0.7A if driving
both windings (suggesting a lower supply voltage).