What I tried that seemed to work really well, is cut the clip you want to use and place it in a separate sequence. Then export as an image sequence. Then take the images made, import them into photoshop and do your masking and whatnot. I cannot stress keeping the images labeled in a way so you know what order they go in. When you are done, import the images into Premiere. I like to make a separate bin just for that image sequence. Then place them where you want them in your main video sequence with a length of 1 frame and you are done.
The hardest part is the masking. Everything else is rather simple.