What type of mattress best for side sleeper !!!

Hi Looking at buying new mattress?bed. What in your opinion is best type for side sleeper likes medium firm mattress. Partner likened to Zebedee during the night and is waking me up constantly with movement. Have looked at Hypnos pillow top and Sealy Posturpaedic both of which seemed good Do you have any other suggestions? The base i have for king size is excellent condition, but will replace if deemed better... Hope that makes sense...ps Both of us not very large people