well it depends, that seems well, and pretty much any modern GFX card will be good, im guessing your not wanting to play the best games. but first of all u gota know if it'll be compadible, whats your motherboard? use CPU-Z, google it
slow internet is caused by bloated antispyware programs. Hardware has nothing to do with your slow speed.
1.basic firewall (inbound/outbound) zonealarm free version
2.avg 8.0 free version
3.firefox browser 3.0
4. use the free "returnil" program when you surf the internet, it will protect you from malware and not slow you down.
Also close all those programs that run in the background in your system tray, the ones that you don't use. They all use RAM while often doing nothing for you.