With the help of the members of this board, I just purchased a pair of Energy C5's for the front and a pair of C3's for surrounds. I was thinking since I have to buy stands for the C3's anyway, why not just buy floorstanders for the rear. So, my question is do C7's match well with C5's (with their different woofer sizes)? I'm choosing between the following options:

1. buy another pair of C5's for the rear and return the C3's
2. buy a pair of C7's and move the C5's to the back
3. keep the C3's and just buy some stands
4. buy C9's and move the C5's to the back (would rather not spend the extra cash to do this, but would consider it)

I currently do not have a center or sub, but do plan to get them. My living room is 15x15x9, but it's not separated from the dining room, so the room is actually 25x15x9. I live in an apartment complex so I don't plan on turning the volume up too high. Thanks for any advice.