For spectrum I always used Fuse on both Linux and Windows computers -
http://fuse-emulator.sourceforge.net/
I also use Fuse core on RetroArch (RetroPie, Battocera and RetroArch+LaunchBox on PC).
Another emu that I have also installed is ZX Spin.
Spectaculator seems really nice emulator, but I just don't want to pay for it.