I just bought an OBERHEIM OB-12 and a NOVATION K-STATION and they are both excellent synthesizers . I would have to say that going by our past discussions and what you have told me and everyone else about what it is you like , I can say this .
Roland RS-5 and RS-9
Korg Triton LE
Ensoniq ASR-88
YAMAHA CS-1X and CS-2X
These you will not like , they are boring sample playback machines .
If you like the simplicity of the ARP synthesizers that you have and you want to just be able to build you're own sounds then here are some good ones .
KORG POLY-6 , KORG DELTA , KORG SIGMA
ROLAND JUNO-6 , JUNO-60 , JUNO-106
YAMAHA SY-1 , SY-2 , CS-5
NOVATION BASS STATION , A STATION , K STATION
REDSOUND DARKSTAR , DARKSTAR XP-2
FUTURE RETRO 777
PAIA 9700 MODULAR
SEQUENTIAL CIRCUITS PRO-ONE , PROPHET-600
SIEL DK-600 ( OPERA 6 )
I think these will do what you want and they will not KILL you're wallet .