Upgrading ram and processor

I have a mid 2010 white macbook, it become slow after I upgraded it to Mavericks. I would like to know if I reinstall the original OS it will be a bit faster or should I restore the original OS AND upgrade the ram and processor? If I go with the latter, on the Apple website it gives me this ram: PC3-8500 DDR3 1066 MHz. I've researched many brands on Amazon and some people cite problems after installing various brands. Can someone advice me toward a good ram and processor that wont cause any problems? Much appreciated!