Syndicate Wars was never released for the Amiga (unfortunately, only thing that made me jealous of PC owning friends).

However I think the original poster may have been referring to FreeSynd which is an open source port of Syndicate not Syndicate Wars. I couldn't find any info on an open source Syndicate Wars port.

If you do wish to play Syndicate Wars then I'd imagine dosbox would probably do the job.