connecting 2018 Mac Mini to 2 27" Thunderbolt displays

I've currently got my 2018 Mac Mini connected to a 27" Thunderbolt display via Thunderbolt 3 USB-C to Thunderbolt 2 Adapter and a 27" Benq via HDMI. I have an opportunity to inherit (figuratively speaking) a 2nd Thunderbolt display and am contemplating replacing the Benq with it. My issues: 1. I don't want to have to drop $50 on the adapter. Is the Apple version the only one out there? I've found USB-C to Mini DP adapters for quite cheap but my understanding is that it *has* to be Thunderbolt... mDP alone will not cut it. Is this accurate? 2. As a measure to avoid the $50 hit in #1, can I daisy chain the 2 Thunderbolts? I believe I have a TB2 cable laying around. Otherwise, it looks like I'm stuck with a $30 hit for that... or is there a non-apple version I'm missing?