You will stuggle.
GWX 1.03 will run fine on the recommened specs.
You might be able to improve performance by using the optional 'Light Habour Traffic' mod that is included.
Don't worry, lockups etc are common in SH3/GWX especially when convoys/ships come into rendering range.
If you are going to upgrade, I suggest:
2GB Ram
X800 Pro ATI (best choice for the money & will allow full GFX)
