Question Trainer and trekking bike Kellys Lagoon compatibility

[benmal]

Hello,
I have quite old trekking bike Kellys Lagoon (Here is the link to specs). My bike have Shimano Alivio with 8-speed cassette. I would like to buy interactive trainer and I have two options: Direct Drive trainers like Tacx Flux, Elite Suito or trainers with wheel like Tacx Bushido, Tacx Genius, Elite Rampa, Elite Tuo. I have few quiestions:

1. Is it it possible to use my 8-speed cassette od direct drive trainer? I read in specifications that kind of trainers are compatible with 9/10/11 speed cassette. But some people told that it is possible to use 8- speed cassette. Where is the truth? If it is not possible I will have to change my cassette, gears and everything. It's costy...
2. If I buy non direct drive trainer like Elite Rampa etc. may I use my rear wheel and only change tire to use with trainer?

Thank you for your replies in advance.