Aftermarket radio, lowering kit, ecu chip help!!! please

I put almost a thousand dollars into my car and now I am ready to keep making my 2001 Celica GT better! I bought a radio install kit that doesn't fit radios so I was wondering if someone could explain that! I also want help picking out new struts and lowering springs and want a good height to drop it! And does anyone know what output a celica makes hp wise after Jet Performance chip mod? Thank youuuuuuuuu!