You can get away with just replacing the springs, but it will save you headaches if you buy struts as well at the same time. Also even better is if you can get a matched set (springs and struts designed to work together). If you get springs and struts, you will also need to get and alignment done, and you will need camber kits to do the alignment properly because if you don't your tires will wear. The ideal would be to get adjustable coil overs so you can change the ride height but it all depends how much you want to spend. As for brand, everyone has different tastes for ride height, comfort, and stiffness. I personally like H&R and Eibach, and think that Tokicos are a little too stiff, but that's just me. There's other good ones out there, so i'd ask around and see if you can have a ride in some cars that have different set ups so you see which ones you like. As for price, i'm in Canada so you'd have to talk to one of the other guys here about that...