My current console (clarion cx501) is bumping 50x4 to each of my doorspeakers, (2 up front, 2 in back).
No it's not.. you're getting about 20wrmsX4. Cooling, size, and current limits mean that any deck you get will be getting about 18-20wrms per channel. Unless it's a dual, then you get like 10 cuz they suck.
Anywho.
If you're trying to get the most out of those speakers, don't bother messing around with bridging outputs and crap from the deck. You're best to just get a 4 channel and be done.. more ability to tweak and give your speakers the full power they're looking for.
If you're planning on running a sub, set the high pass filter somewhat high to cut some of the lower notes to the speakers, then run most of your bass through the sub itself. Otherwise if you're not looking to run a sub, feel free to run as much bass as you'd like to the speakers, if they're properly powered you shouldn't run into issues with muddy sound until you physically reach the speaker's limits.