A speedup no hardware needed. You said Java 6 min for games.
I would start with the Java environment remove all versions from control panel / add remove programs .
Get SDK flavor of java from here
Java SE Downloads
See how that goes for the
Games, P.M. me for details of problems with java retail flavor.
I would do a fresh install after backing up critical files, I have had the boot time up to 6-7 mins on a PC reduced to 1.5 mins. However it may take you some time to get the system back to normal eg drivers.
Another option
Add more Ram buy brand new from China Ebay etc cheap.
Another option
Replace Hdd with a 7200 rpm one, will make programs load faster.
If you did do an upgrade package is it possible for you to do the hardware shuffle. eg you use the new upgraded pc and hand down your old one changing a few bits like video card.
Another option is buy a S/H PC with better specs and transfer all the data and maybe the video card.