one option is to add the moshi ivisor ag for anti glare
for hdd there seem to be two schools of thought: 500gb 7200rpm for faster performance (but less total capacity and less battery life) or 640gb 5400 rpm (more capacity, better battery life). wd scorpio blue or black and seagate momentus are some popular brands. everyone has their preferences/opinions, just do some searching.
8gb ram is pretty pricey. for most people 4gb will be enough and worth it. unless you really know you need 8gb and/or can afford it, i wouldn't bother. owc is a popular option. newegg, crucial, etc. are popular too, just do some searching again.
hope this helps.