Need help using blu-ray digital download file

[alba17.livejournal.com]

I hope someone can help me with this. I've searched and searched for answers but I'm not coming up with an obvious solution. For the first time, I'm trying to vid using the digital download that comes with commercial DVDs and Blu-rays. I'm making a Captain America vid with clips from both movies. I converted the files to .mov (I use Final Cut Express) and made clips with MPEG Streamclip. For the life of me, I can't figure out how to handle the weird frame size for the second movie (from Blu-Ray). It's 1280 x 532. I converted the Blu-Ray clips to 720 x 480, the size of the first movie, but they're still a different size from the first movie when I put them into FCE. When converted, they take up the whole frame, while the Cap 1 clips are letterboxed. In the past, when I've had different size sources, I just manually adjusted the frame in the Canvas and it wasn't a big deal, but I can't seem to do that with this. If I scale the Cap 1 clips up, it cuts off too much material and I just don't see how it would work.

I guess I have two basic problems:

1) How can I make the two sources match in frame size?

2) How do you handle Blu-Ray digital files with this weird frame size? Even I were making a vid with just Cap 2 clips, the natural size is so short and wide. It only takes up the middle third of the screen. The other weird thing is when I check the size of these clips in Quicktime, it says it's 720 x 480, even though I exported them to an HD frame size.

I'm so confused and frustrated.