if they are single coil subs, you put one sub on each channel. you'll get a stereo 4 Ohm load.
If they are DVC subs, bridge the coils of each sub in parallel for a 2 Ohm load, and place one sub on each channel for a stereo 2 Ohm load.
ideally with a 2 channel amp, you'd want two 4 Ohm per coil DVC subs, or keep those Audioblah subs you purchased, and get a monoblock sub amp to drive them. Otherwise you can't get an ideal load from a stereo 2 Ohm stable amp, and two 4 Ohm subs. sorry.