Hey Daniel,
Short answer: Yes the EP2500 will work. Long answer: you'll need to buy another piece of equipment to do what you want to do.
Looking at this manual for your receiver (
http://www.jmargolin.com/marantz/manual.pdf) I see that you have a set of pre-outs you can use. On page 3 in the manual it says:
"Special jumper plugs normally interconnect these MAIN IN and PRE OUT jacks. Removing these two plugs allows you to use your 2230 as an independent basic stereo amplifier and/or an independent control center"
Now you could use something like this:
http://www.reckhorn.com/index.php?ln=en&prod=f1
It is available here:
http://www.creativesound.ca/details.php?model=F-1
That should allow you to go from the PRE OUT on your Marantz, to the input on the F-1, the you'd go from the SAT OUT on the F-1 back to the MAIN IN on the Marantz. And of course go from one of the sub outs on the F-1 to the EP2500.
Thats probably what I'd suggest.
Oh, which BTL do you have?