Well with car audio you get what you pay for.
For decks Id go with kenwood, alpine, pioneer
For subs Id try any of the big name brands JL, Kicker, IDMAX. However, I would encourage you too look into RE, Diamond audio, Adire Audio. They arent as big but they are just as good quality wise.
Amps go with JL audio or PPI
Whatever you do if you get subs make sure the quality of the box is TOP TOP notch. If your box sucks ass your system will suck ass. Other than that just do some more reasearch. Go to a local sound place, not best buy or good guys. Im talking privately owned. They usually have fat ass setups with lots of brands to listen too. More than likely they will answer any questions you have.