My reply on the same question on DCRainmaker(dot)com…:
Fluid trainer such as a Saris Fluid2 or Kurt Kinetic Fluid and a speed sensor. Depending on where you are these are found used for ~$150. Get fluid…do not mess around with magnetic. Other option is to check Zwift for compatible trainers. Somewhere on their website. Compatible means they have a Speed vs resistance curve for the trainer and Fluid trainers are reasonably repeatable.
A much experience can be had with a wheel on SMART trainer such as Wahoo Kickr Snap or Saris M1/M2. Search around and you should be able find one used unless you are in the woods. Wheel on means it will work with just about any bike. If you have a road bike get a trainer wheel…$30 on Amazon or wherever. If a mountain/hybrid, get a slick with a solid casing and not a glue on tread. The glue will melt from the heat. Elite and TACX have their versions and are probably more available in Europe.
Direct drive but if you have less than 7-8 speeds, might not be possible. Or at the least, difficult/PITA.
Money to burn:
Get a bike: Wahoo Kickr, Tacx, Watt bike (although some issues with Watt bike per Zwift forums) and Stages. DO NOT GET A REGULAR SPIN BIKE WHERE YOU MANUALLY CONTROL RESISTANCE…SCHWINN IC4/8, PELOTON, ETC. It will become an exercise in frustration.
If you find something and are not sure…ASK before purchasing. Just because the device claims Zwift compatibility does not necessarily mean it is so…SCHWINN…Here or on Zwift forums people will readily help you out.
Good luck…it can be addictive…it got me to climb the Zwift Alp and I have weight, age, and inability to breathe working against me.