Buy a kicker, neo, elite, or cyclops hammer..big screen tv and a nice fan...

If you don't you will eventually and be kicking yourself in till you upgrade whatever you settle on...trust me. Smart trainer + Zwift has doubled my yearly kms to almost 25k and turned my ftp vo2 max and stamina though the roof, with structured work outs and not being bored outta my mind like I was using trainer road.