What would happen if I hooked up a Rockford 201s amp to 2 Sony Xplod xls 1236 12" Would I be Over/Under powering them? Anything else that could be a downside or upside? specs are below....

Amp:

100X2 @ 4 ohms, 200X2 @ 2 ohms, 400X1 @ 4 ohms, 50-250 Hz 12dB variable HP/AP/LP crossover, RCA and High Level Inputs, Remote Punch Bass, Solar-Tex Cast Aluminum Heatsink. Punch DSM, TOPAZ, MEHSA, NOMAD, INDIGO, and TRANS-ANA circuitry


Subs(if you can give me more specs on these that'd be great):

900 watts max, 350 watts rms each

those power ratings seem strange

100X2 @ 4 ohms
400X1 @ 4 ohms
how the power goes up 4x with just one load instead of 2 is beyond my comperhention

If you hooked the subs up in Parallel then you would give the amp a 2 OHM load. The amp would then put out a good chunk of power to drive the subs. You just have to make sure that your amp is stable to 2 OHMs bridged (not stereo).

__________________
Music sounds better when it's loud.

These specs are typical of a Class A/B amp. 100x2@4 0hms (total of 8 ohms seen by amp), 200x2@20hms (total of 4 ohms seen by amp), 400x1@4ohms (total of 4 ohms seen by amp)

I'm betting your subs are SVC 4ohms (single voice coil 4 ohms each sub) and in that case you can only wire them in stereo for 100W to each sub or in series for a final load of 8 ohms which when connected to your amp bridged will still cause it to produce 100W to each sub (200W total, same as wiring in stereo.

So either way with those subs you can only make that amp put out half it's max power.