frame size and compression

[jdmoviemaker]

Anyone know of a good frame size for myspace tv?
The default is 425x360 so I want to get the best quality possible
for a video shot in squeeze mode or letter box on my dvx &
I plan to export my video on mpeg4.
Is there a better format?

My idea is to

-shoot squeeze mode
-edit & export to mpeg4 frame size 425x360
-upload to myspace tv

is this good? because I want the best quality possible.
Does anyone know of a good compressor for uploading video?

I just want good quality and letterbox bars (for the 16:9 look)

Thanks