There are plenty of sites, it is best to find out what you want and search for it in google. As Glass would say google is your friend. You can always find reviews on stores if you are worried about shopping with them. Many stores also price match like cardomain.com and acaraudio.com. Just beware. Many products sold on the net are not covered by the manufacturers warranty.
Check out the deal by the Ebay seller "audio-n-video"
He is an Ebay powerseller. I just bought an Alpine sub and Alpine amp for a killer deal from this guy. He is also super friendly and answers questions lightening fast. I believe he has an Ebay store set up, but he will cut you a deal if you go outside of Ebay (because he saves on Ebay costs). He has tonnes of different products . . . before you buy anything, contact him for a price first
