How to make a large LED chase effect? Answered

I am looking to make a Xmas jumper with an LED chase effect to mimmic the snow falling.  I am having difficulties in deciding which is the best way to do this.

Essentially Think of having 8 strings of 8 LED's (to make it simple) and each string will have its own chase effect running.  I want these to be independent of one another, I.E. I don't want a constant LED line running down the jumper.

Now I have thought of two ways of doing this via Arduino:-

1) Simple Method - Using the ATMEGA328 to run each string of 8, providing its own running time and speed.

2) Difficult Method - Use a grid where one ATMEGA328 can run a 8x8 matrix.  This would require some transistors at each row and column and fancy code to produce the right effect.

Disadvantages of 1&2

1) Lots of wiring, 8 ATMEGA chips and power supplies

2) Unsure if this is possible, obviously I can switch quickly but to the eye would this even be visible.  For example if I wanted to power column A and row 1 and simultaneously power column D and row 5... would this power said LED's and also column A row 5 and column D row 1, all at the same time?

Any help would be greatly appreciated.  If I have overlooked any other methods, please feel free to mention them.

Thanks
Mo