sorry for whatever is repeated.
You do not want to wire one chanel to each coil, this could be done but shouldn't since 2 outputs generally aren't exactly the same. You may not have problems, but you may though.
You need to know the impedence(ohM) of each coil. with 2 4 ohm coils, you can get 8 ohms or 2 ohms.
with 2 2 ohm coils, 1 ohm or 4 ohms. So for 2 subs, you can get 4, 16, 1 ohms OR 2, 8, or .5 ohms, respecively.
You also have to see what impedence the amp is rated at to get the most out of it. For subs, you typically wire in mono, so you want the bridged mono impedence for max power on the amp

javi d
vroom n' boom