you may not get what you want for $350 unless you're buying low-end hardware IMHO. If you want more bass you may have to sacrifice a little performance because you drive a light car 10" would be ok, they tend to be very punchy, 12" would give you better bass, but again with the $$$ if yo want to run your door speakers, rear speakers AND a sub off the same amp, you would need to buy a 5 channel amplifier, and you would probably want a head unit with sub control. Problem is that everyone's opinion on sound quality, and good sound differs, so shop around everywhere you can, first for what you want, and then for the best price.