Does the Wheatstone have ASIO drivers? If so, select that in Audio System and see if Reaper gives you some choices for in and out.
ASIO4ALL might be a good one if there are no native ASIO drivers for that piece of gear. It wraps around ASIO-less audio drivers and has worked for many people for years now.
ASIO4All
Your image for Samplitude is not correct. It should be like the image I've attached.
Also, in Reaper's Audio System, have you clicked on the drop down list to see if ASIO is listed?