I have a football forum. It gets about 300 to 400 unique visitors a day on any normal month. When there's a major competition during that month, I will get about 500 to 700 unique visitors a day.

My ajax chatbox in the homepage is being used very frequently by members, so much so until my web host advised me to shut it down. I'm currently on a shared hosting. And everyday, members will post football related pictures in the forum.

If I get a VPS with the following specs, how fast will my site be?

80GB Disk Space
1024MB Ram
500GB Monthly Traffic
100Mbit Connection

Any experts in here? I'm a noob at web hosting.