Advice for PC upgrade

Hi, i'm thinking of upgrading my PC (aimed at gaming)

my current spec is

Gigabyte GX7+ motherboard (i think!)
512 mb ddr ram (266 i think)
Geforce FX 6200 (256 mb?)
Athlon XP 2400+ (or 2200?)

sorry i'm at work as i post so cant remember exact spec

anyway, i'm thinking of getting two gig ram and an external 250 gig hard drive but my question is, should i consider replacing the motherboard and/or processor.

My main concern is playing the forthcoming LOTRO and getting FF XI to work at some point. obviously FFXI should be ok but LOTRO is more questionable.

any thoughts?