Vintage Synth Repair

I'm looking for any advice on what would be a good 
vintage synth to buy. I've only used a Kurzweil K2000,
so I'd prefer something that's reliable and not too 
difficult to operate. Any input would be greatly
appreciated.

Thanks,

Jim

P.S.  I'm new to the group, but that julie_bells276 sure 
seems like a nice girl.