I'm just debating which amp to go with. Since I have sony xplod deck I would like to keep things the same. While checking out now. I can't really decide I should go with a bit of old school or a newer model. I know I want a 4 channel amp for my front and rears. I was thinking some thing like these models: SONY XM-504X ebay link SONY XM-460GTX ebay link #2 I don't know if I should go with something a little older or a newer model? Which one would you pick? The XM-504X appears to have a few more toys on the cover. I've been out of the car audio loop for a few years now and I'll just slowly getting back into it.