amp ohm

When trying to match an amp to subs, different rms watts are listed on subs, so do I look at the 4 ohm number, since my subs are 4 ohms, or do I look at 2 ohms, since the total speaker impedance will be 2.66 (wired parallel/series with two sets of 3 in parallel, and the two sets in series)? I...

G'morrow gents, So I know some of you are tired of seeing me post a bunch of crap, but bear with my noobiness for just a little bit longer. So my Boss PH3000D is blown and I'm now tasked with finding another amp. I seriously don't want to fk up my next purchase so I'm back here asking more...