I've seen the piggy-back L293 before but can't help think it's a poor solution as it is a bipolar device and won't share current equally. Plus, it wont dissipate anywhere 2X the heat.
Note that the spec'd current is all about heat dissipation (ok, almost all...). If you can't get rid of the heat, the chip dies. You should try to understand how much heat your application will generate - I'd guess around 1 watt per motor for 4 watts total. (4 * 1.2V * .8A) I don't think a dip or two, even with a heatsink, is going to cut it. Use the L298 with a sink...
Jameco has L298s for less than $3.