Exporting from iMovie 09 for iPad and iPhone/iPod Touch

I recently bought an iPad. I have some video imported into iMovie 09 from a Sony HD video camera. I previously exported them so they would play on my iPod Touch but I decided to re-export them in a higher resolution using the Apple TV template to take advantage of the higher resolution of the iPad. I chose Apple TV template vs 1280x720 template to save some space. Anyway, I am not able to sync those new videos onto my iPod touch because they are not compatible.

What format can I use in my export that will retain at least the Apple TV resolution of 540 lines but also play on an iPhone/iPod Touch? Is this even possible using iMovie?

I know the "Digital Copy" movies I download from my Blu-rays will play on both and are great quality so I know it is possible. Just want to know if I need to buy something like Final Cut.

Thanks for any help.