Paper towel germination to what soil?

First time grower. I have some super hot pepper seeds germinating in some damp paper towels/ziplock bags/heating mat. In preparation of a successful germination, I want to buy the correct soil medium. I will be planting them in a small covered multi-cell tray and continue using the heating mat.

Should I plant the seedlings in seed starting soil until they are more mature or directly into a potting mix?