need some amp help

Ok heres the deal i got 2 12" dual subs 1100 watts with a 460 watt amp(ik its not a lot but it bumps) now i just got new rear speakers for my car 400 watts 64 watts rms (ik terrible) i want to get a 200 watt amp with 80 rms so it will work even. but i want to know what do i do about RCA wires if they are in the other amp because my deck only has the output for 1 set of RCA cables. Is there a splitter that will make 2 into four our how could i do this thanks guys appreciate it again!:confused:

you need an amp with RCA output. i just got one for my car. a JBL. so i can run the sub amp through my main 4 channel amp.