I got the engagement ring from Etsy. ArrowheadMoissanites.
The middle band is from Amazon. https://www.amazon.com/dp/B081RLMFGR/ref=cm_sw_r_sms_apa_i_c0WkFbFVFA8T9
The bottom band was custom made by a local jeweler, but it's based off of catbird's Curved Snow Queen Ring