The most critical accessory will be the steamer basket – because the feet could scratch the coating, I recommend getting a silicone one. Containers, ramekins, etc. that will go on top of that steamer basket can be made of any oven-proof materials.
Here are my recommended electric pressure cooker accessories:
http://www.hippressurecooking.com/3-must-have-accessories-for-electric-pressure-cookers/
Here are the containers you can use in the pressure cooker:
http://www.hippressurecooking.com/pressure-cooker-accessory-forms-and-molds/
Welcome and let me know if you have any questions!
Ciao,
L