Epson for me is the best manufacturer of scanners and printers but seems to have failed with providing the driver for Windows2000 for the GT-7000.
Here it is!! (it's the twain you want to install)
After my GT-7000 got stolen I bought the Perfection 1240U. It seems to be exaxtly the same machine except for the looks so I provided you also with the driver for this machine. It has the latest twain. (Probably based on mine)
I hope you like it. Have fun!