Just ordered my new pc, how many leagues ?

Well i have literraly just ordered my new pc, it looks excellents but im just wondering how many leagues i will be able to run on it while still having a fast game speed ?.

The main specs are ;

Intel i7 CPU overclocked to 3.4ghz

Ati Radeon 5850

6gb DDR3 Ram

1tb Harddrive

Good motherboard etc

Im hoping i would be able to run near enough all the leagues in a Large Database, but i dont wanna get into a game and find out that i have run too many leagues.

Cheeeers