Perfect Computer Specs For FS2004

Hello all, havnt posted in a while.
Had kind of a break from FS2004, got back to my computer
and decided its time to update it.

i dont know my specs by heart as im away from it right now,
would like some help on the perfect specs for FS2004.

Ive got a pretty decent graphics card, but im not exactly, brilliant
when it comes to computer equipment.

i dont want to be spending to much on these updates, but could anyone help/guide me through some of the things ill be needing.

i fly alot of long haul flights, prefer the A340, A380, B747, B777 ect.

would like to use, real world weather, just want to stop the lag i get, and increase the detail.

i would also like to install add on's, airports, scenery ect.
i had heathrow, birmingham, JFK, Dubai, and i think LAX before i had to re-install alot of things.

look forward to reading some replies if possible, thank you.

Tom..