5ch amp

I have an old Aiwa CDC-X217 deck, which has a broken internal amp, so I need to use the amp to power my component speakers (Rainbow Dreamline 230.02).  I won't have any rear speakers, because the back of my car (94 mustang coupe) is so small.  The deck has one set of pre-outs, and the amp, an Earthquake TNT900, has 3 sets of RCA inputs, all of which I plan on using.  One for the components speakers, and one for each sub (Earthquake BR12's).

So my problems are:  I need to get one pair of RCA's into 3 without losing all my power, and I need to bridge the rear outputs on the amp to run one sub, but there is no low pass filter on the rear outputs.  And I have about $30 to spend and wont get more anytime soon.  If you have any cost-effective ideas for getting this thing running, please help me out.

And yeah, I know the equipment is all crap, but I only paid like $260 for a whole system with reasonable power output.