Not quite sure what the issue here actually is - you'll be working with PAL footage after you have converted it, and you'll need to make PAL sized menu assets, too.
Set DVDSP to work as a PAL project and import the assets in exactly the same way - all else is identical, it's just the actual format/frame rate that changes.
For what it's worth, I'd be looking to shoot in PAL as well, but the converter does a good job (and is a tad cheaper than a new camera!)