Suggestions for Fosgate installation....

I'd suggest running one sub bridged on the Left channels (left and right), and 1 bridged from the Right channels (left front / rear and right front / rear).  You don't need to worry about parallel or series because you are wiring the subs to different channels independently.  Even though they will be bridged, sub1 will never be connected to the right 2 channels, and sub2 will never be connected to the left 2 channels.  If you were running a 1 or 2 channel amp that was 2 ohm stable, then you would wire the subs in parallel giving you a 2 ohm load for maximum output.

in response to "I'm not sure if I should bridge it according to the manual or just bridge it, one sub hooked to the front outputs and the other sub hooked to the rear outputs "... I just checked the manual (page 8) for 2 channel wiring of the 700x, and bridging 1 sub to the left and 1 sub to the right is how Rockford recommends.  So I'm not really sure what you were asking because both of your scenerios (the manual vs. your description) appear to be the same

Make sure to read the notice from Rockford concerning your amp... http://www.rockfordfosgate.com/ez2/fcsscripts/ExternalFiles/Rockford/2002/Amplifiers/LIT4216_RCA4Ch_NOTICE.pdf

And this should be the manual for it as well... http://www.rockfordfosgate.com/ez2/fcsscripts/ExternalFiles/Rockford/2002/Amplifiers/MAN3771C_4ChPunch_MAN.pdf

I gotta be smok'n something 'cause my reply was incorrect.  Rockford's suggestion is bridging left and bridging right (not front and back like I said before).  Sorry 'bout that. I've already edited my last post, so it should read correctly now.

I thought that's what you were thinking, but I wasn't sure.  Actually, Rockfords suggestion is for:

LR+ plus LF- for 1 sub, and RR- plus RF+ for the other

What you're asking for is bridging Front and Back, instead of Left and Right.  It should work (their 3 channel wiring diagram shows LR+ plus RR- for 1 sub), and it should be LF- plus RF+ for the other sub.  So on that you are correct.  I'm forced to ask why you would want to do this though?  Most people running 2 subs would prefer to have balance in the subs for the stereo effect, not a fade affect.  So I would still suggest using Rockfords method of LR+ plus LF- for 1 sub, and RR- plus RF+ for the other