Hi!
TL;DR yeah get a NExT.
NFC is just another form of RFID. We usually distinguish by LF low frequency 125khz (“RFID” note the quotes) and HF high frequency 13.56 mhz (NFC).
NExT is just xNT and xEM.
xSIID is basically just xNT with an LED.
SLX is a special chip you kinda only wanna use if you have locks that require SLX.
M1 Mifare Classic cards with 4 byte IDs are very present, it’s very likely you have used an M1 system before. Magic means you can change the ID, you can clone cards to it. There is no other benefit, except that you can use it with systems that require it.
NExT sounds about right for your usecases. There’s a slight possibility that xEM wont work for your LF card, but I doubt it.
You might wanna get an xM1 too for hotel cards or stuff like that.
The Dangerous Things YouTube channel has quite a lot of info.
I can also recommend the interviews on Amal Graafstras channel.
Unlocking phones is kinda impossible, at least it’s not easy (or not really locked to begin with).
Yeah on a competitors site, but you could just use the xEM if your LF card is an EM.
I guess you know payment conversions exist aswell? 