I’d go for either a DX7 or ESQ-1. I would suggest an SQ-80 but the keybed sucks ass and it’s pretty ugly. ESQ-1 sounds GREAT. It was trying to be a digital synth back in the day but it’s really a hybrid, which gives it a really unique sound. Plus the keybed and build quality is really robust. It is multi-timbral and the built in sequencer is really easy, fast and fun to use. I currently have an ESQ-1 slaved to midi clock from an MPC2000xl and it is rock solid… and this is with the ESQ-1 using its own sequencer instead of the MPC sequencing it. Also, if you wanted to run the ESQ-1 in multitimbral mode sequenced externally, that’s easy to do. The sound is like a poor man’s fair light. Look up the sound “wavbel” and you’ll get the idea on how good this thing sounds. It’s probably a better sounding board than I am a programmer most of the time.

My other suggestion would be to go for a DX7. They are cheap and they are VERY good, VERY slept on. I treat mine as a sort of rompler as I downloaded like 10,000 patches at some point in time. Most of the time when you think of DX7 you think of those cheesy typical 80s sounds, however there are some VERY choice sounds to be had from this synth that have a lot of staying power over and over again in modern music. Plus with those thousands of patches you can find online, you will find more choice sounds that are just killer and you may use over and over again. I use two Whurlitzer piano patches all the time for instance. Plus the keybed has an excellent feel, probably the best synth action out of anything I’ve ever put my hands on. It’s got almost a semi-weighted feel going on; it feels and sounds like a REAL instrument. Get one of these for $200 and it’s a no brainer.