For long Hoya stems like that I always use a shallow pot with lots of drainage holes, or if I don't have shallow pots on hand, I use a plastic saucer/catch tray and drill lots of drain holes in the bottom.
Hoyas require really good air circulation around their roots so I've always used the mix I learned about from a Hoya nursery grower years ago; a combination of a small amount of potting soil with lots
of orchid bark or coconut husk chips added in. I fill the pot almost full and lay the stem atop the soil, coiling it around in a circle to fit inside the pot or tray. I then weigh the stem down in a couple of places with small rocks to keep it in contact with the soil. Roots will form at each node and eventually new stems and vines will emerge.
I'm sure others will be along with advice on how they propagate and grow their Hoyas. Please keep us updated on how your plant does for you!
Here's our database entry with information for your Hoya and member photos: Sweetheart Hoya (Hoya kerrii)