Parts express and build your own components. Dayton audio and Vifa are two companies to look into for "cheap" comp sets. They also have the Pyramid W64 6.5s that sound really good for the low price point IMO. Then you have the ever popular Seleniums that sound amazing for the money.
If loud and punchy is what you're after (that home theater sound) you might want to step up to larger drivers - 8" or 10" mids. They'll dip a little lower FS wise and you can x over closer to your substage to get better imaging.
In the end it's your car and your ears so only one person HAS to like it - You.