Ha. I'm digging the name.
If you opt for coils instead of springs, your three biggest mods (can't speak to the speakers, so I don't know for sure) are probably going to be the rims and springs.
My coilovers cost me $1000 and the wheels I just bought cost me $1200 for the rims alone, but prior to buying those, I was looking at a total of $1300 for another complete wheel/tire set. Only reason I opted for the nicer tires is that when a set of $3200 wheels wanders through your life asking only $1200, it's hard to say "No."
I'd recommend checking out these two sites:
http://www.racinglineperformance.com/
http://www.stillen.com/
You should be able to find most every performance mod you could want for your car at those two sites. I haven't looked around at many other sites, so others may be able to add to the list.