Sick-Flix.com is a horrible place. You can't get access to all the movie "torrents" without paying a donation fee.
One thing to keep in mind... you don't need movies that are 3d for evo 3d, you just need a 3d movie. Luckly unlike images, there is only 1 true 3d format for pc use, and that is side by side versions of movies. Any 3d movie you will find on pc, either in mkv or mp4 format are side by side. I am totally ignoring anagrams of course. Now to find these... well there is good and there is bad. The good news is you can find blueray rips of movies in 3d all over the torrent sites. The bad news is they are almost always 1080p since 720p is pretty bad for 3d on large TVs, A lot of detail is lost squeezing 2 images into 720p. IF by chance the 1080p video file is compressed in a way that the evo 3d can use hardware decoding then it might be possible to do a straight copy and play of it (although a 1080p 3d movie is going to be 15+ gigs). Otherwise you will have to do a resize and recompress of the entire movie down to 720p or 540p.
This could lead to some issues, I am not sure what method the evo 3d uses to detect 3d video files. As we have seen on youtube, the low bitrate version of videos it plays over 3g have been known to cause the device not to initiate 3d mode because it cannot detect the center line for side by side video streams. Resizing down properly might be an issues, I have not worked with 3d editing yet. I do know sony vegas will handle editing and compressing of 3d videos though.