If you have the electrical (big 3, new batteries (deep cycle), 1/0 or 4/0g power wire and ground wire, and a H/O alternator) to run two powerful amps then
by all means get 2 amps..
if not just run 1 amp that does rated power.
I installed 2 of those Premier 3001D4 on 1 SAE-1000D amp they wanged just fine.. just make sure you have a good enclosure built.
I always stress good a electrical because if you plan on upgrading to more powerful amps / subwoofers its always good to know your electrical can handle it....