Major help needed with AMD Athlon XP 2.4Ghz

[MG44]

Am part of my local Air Traning Corp Squadron and am trying to upgrade our flight sim.
As funds are tight am trying to squezze as much out of our old rig as possible.
I want to over clock and could idealy do with a better heat sink
Iv canabilised old PC's that the cadets have to get up the old system to the new one

CPU: AMD athlon XP 2.4Ghz
RAM: 2gb DDR 200Mhz
GPU: AGP ATI 9800 Pro 128mb
PSU: 250W

does any one have any surgestions on what, if anything is still availible from this type most web seraches have got nothing

HELP

 

[MG44]

iv looked at uping the proccesor but am not sure wot will run off the AMD socakt A 462.
We r hopin to get a grant but the chances r very slim. if we did id build use a PC on the cheap
il have a look at the item