Another option could be the line 6 M5. They go for very cheap these days and have all the synth and filter sounds of the FM 4, purple stomp box modeller, plus the others too. I used to have the FM 4 years ago that I used with an expression pedal with for a live drum and bass band. I've been thinking about buying the m5 just to have those sounds again plus the delays and modulation stuff. Effects that I'd never use enough to buy a standalone stomp box for.
You can actually download the line 6 vst as a free trial to try out if you have a computer interface.