Having the same speakers for the front is very ideal. In fact having the same speakers all around, at least five, is ideal for hi-rez music like DVD-A and SACD. Just be aware that if you have a CRT based TV, the speaker that's near that tv has to be shielded to avoid magnetic anomallies on the picture.
I have 5 speakers that are the same all around. I listen to multichannel SACD.