HD to SD downconvert - Best Results Inquiry

Hello everyone,

Backgrounder: I'm working on a project with a creative slant that "Wants to look home made". The interesting part about this is that they decided to achieve this by actually shooting on an AVCHD consumer camera. After transferring to Apple ProRess 422 with a resolution of 1920 x 1080i (upper - odd field dominance) and a timebase of 29.97 - I have edited in the native format and am ready to master TO STANDARD DEFINITION.

My Goal: Cleanest possible conversion of my timelines from Apple ProRes422 1920x1080i 29.97 - to 601 Broadcast 720 x 486. I also want my framing to be center cut, NOT letterbox, so I will be scaling the HD footage to 50% on my SD-601 timeline.

So Far: Given that Final Cut automatically letterboxes & adds a "Shift Fields" filter with a value of +1 to all of my footage, I'm wondering if my center cut framing changes the need for the field shift. Does center cut add any other possible options to cleanly scale the footage?

I'm curious what experiences people here have had with this type of conversion, as this is my first HD downconvert for broadcast, I want it to look as good as possible.

Many thanks to all in advance. I look forward to your input, and trying out anyone here's ideas.

~john