Resolution concerns in iMovie, will Final Cut Express be solution?

Question

Hello:
I'm working on a film, and have input from various people with various cameras. We are all working with 'standard' definition cameras, however, even among our cameras and outputs our film clips have different resolutions.
I put together a 120 minute film in iMovie. There are approx. 15 minutes of various clips from cameras with less than good quality film. Because of the film quality of a vast minority of the film clips, in iMovie, I can only export it into a 'medium' resolution, because medium is as good as some clips can be made out to be. So the majority of the film suffers with resolution because a small amount of film can only be done in medium resolution.
Does FCE allow you to better blend film clips with various resolution, while still maximizing your final output's quality? iMovie seems to be limited in that your final output is only as good as your worst quality clip that is included in the film.
Can I use FCE or some other tool to somehow compress and clean up the clips that are medium resolution so they can be then imported back into iMovie and can be used in a high resolution output?
Or will FCE natively handle most of what I'm asking, ie, glueing film from different quality standard def. cameras and creating a final highest possible resolution film? There appears to be an export from iMovie into FCE, however som things are lost in transition. I don't want to learn FCE completely or be forced to move to FCE or Pro in order to do something I'm shocked iMovie doesn't better handle.
Or are there any Pro's out there for hire to help me get over this hurdle. I'm making a DVD. The best output I have right now is 640 x 360. I don't exactly know what output is ideal for going onto DVD, but I figure the rest can be done in 960 x 540, so shoot for the higher resolution before compression and have better results, but I don't know if I'm thinking right.
Any input into using FCE as a solution, or if I'm asking something that cannot be done? I don't understand all the codecs and compressions but figure if I can massage the lower quality stuff or otherwise find a tool that help me produce a film project done in iMovie to the highest possible resolution.

Answer 1

.. which vers. of iM we are talking about?
if your source is miniDV (=interlaced), iM vers≤6 is ok.
iM08/09 have that 'skip field' prob, meaning, you lose halve vertical resolution while using iM08/09.
=> this is discussed +in extenso+ at the iM boards. it leads a few folks (incl. me) to establish this web-site:
http://sites.google.com/site/theimovieoutputproject/
if you really need that extra-grain of quality, you have to start from scratch in iM09 or FC/e.
640x360 is no resolution supported by iM (any vers.), nor FC/e.
for sure, +on export+ you can choose this 'size'.
for DVD-creation, use the app's intended workflows to avoid useless interim-conversions.