Arduino on Atmega640

I'm interested in using an Atmega640 with the Arduino bootloader. Since none of the official Arduino boards were sold with the 640, there seems to be no official bootloader for this processor.

I stumbled upon this: http://www.avr-developers.com/corefiles/index.html

However, this is made for the 0020 version of the Arduino IDE. Can I use these files on my 0022?

If not, is there another solution? Or are these boards supported out-of-the-box by the IDE?

Any help is appreciated. Thanks all!

Just got a reply from the creator. Says they will work for everyhing upto 0023. Cheers everyone!