first of all, you have to find the RMS rating of each sub...
since you only have two subs at 4ohms, you only really need one good amp (two channel, or mono....not multi channel)
an easy way to do it is to try to match the RMS rating of the subs to the total power of the amp...
if your amp is mono:
MAKE SURE its 2 ohms stable, if you're gonna wire in parallel, otherwise your gonna have to wire it in parallel/series to keep the load at 4 ohms
if your amp is two channel:
DO NOT bridge a two channel amp with parallel wiring with these subs

...MOST amps will not handle this, use the parallel/series set-up again, or just drive the subs on the individual channels...
that sould do the trick...happy hunting!
Krishan