You need mechanical and biological. Chemical is optional, most only use it if you are removing meds or toxins on a temporary basis.
As for what type of media the best answer I can give is the kind you get the best deal on. You have more than enough capacity, so even a subpar bio media will do the trick.
Look for specials where the packaging is changing or the company went out of business.
My media stack right now is:
Fluval mechanical ceramic rings- got a ton of them super cheap when they changed the package years ago.
2 inch thick pond filtration foam (60 ppi iirc)-bought a bulk sheet it is 5 or 6 years old now
Biological is ceramic bio rings- the two brands I have ordered from are long since gone. I will reccomend ordering a sample size from the seller before putting a bulk order in.