Guide
Open a Reaper Project in Samplitude Pro X
Samplitude Pro X has built-in OMF and AAF support, so it can import the OMF the converter makes from your Reaper project.
Use Samplitude's AAF/OMF import to open the .omf file — it's built in, no extra software needed.
The converter embeds the audio in the OMF, so the import brings the audio with it.
You can convert your Reaper project to OMF for free here.
Going the other way? Here's how to open an OMF file in Reaper.