Jeremy, might I recommend this company. https://www.adtecinc.com/
I use them and own 15 edje units. The sole purpose for these units are to decompress Mpeg 2 files. Adtec in the last year has relased a number of HD players that use the new H.264 codecs. I saw them at NAB and the HD stuff is very cool and great for playback on plasma screens. Check them out.
As for my other question I should have given more info on my gear, sorry. I edit on a G5 tower but I have a Powerbook in the feild and transfer my P2 footage to that while on shoots. I edit with FCP and only FCP. My mind tells me that I should shoot 720p since I can scale it down to SD but I also know the camera can shoot 30p in 1080i mode. It still confuses me shooting in a P format in an i stream if I got that right.
My concern is interlacing when I scale down.
-Lars