Buying movies online?

      I want to put some movies on my Sony Walkman NWA(something something) and really like cheapness(?) of iTunes but, correct me if i'm mistaken, I can't use it because it's Sony. What are some  good LEGAL sites/programs that will allow me to BUY, KEEP, and SYNCH to my sony walkman? And about how much memory would I need for 1 movie? I've got around 950 MB of space left.

Quick Breakdown...
1)Can I synch iTunes movies to my Sony walkman?
2) What are legal sites/programs that'll let me buy and synch movies to my Walkman
3)How much memory will an average movie take up?

Bump before I go to sleep

"LINK"

LOL you need super to convert them to play on Walkmans and no services currently work well with wma players

.......bittorrent....

Just DL that shits, and convert it yourself......