Kurzweil is indeed a good point to go.. Also roland older master keyboards...but of course, they are discontineued.
And indeed...a synth has no specific "quality". It's all about character. Often the keys on a synth aren't great. Can be, but doesn't have to be. Usually, they get controlled by masterkeyboards or other controlled (like squencers, appergiators, computers yada yada yada) unless they are live.
If you like wavetable synths, you can also check for a JP-8000... fun, massive pads (like the well known "Airwave", some call it even Dutch Strings (perhaps because we love to use it in eurotrance).
Juno is i think a different caliber, more retro style...
If you really want something... go for a Korg Oasys ;-) (make sure to save up :D)
To be absolutely honest with you...
Get a good board, like Kurzweil semi-weighted (at least 76 keys)...use both Juno & Kurzweil for different actions, connect it to the computer with a proper starter soundcard (focusrite LE, M-Audio, etc).
Don't spend too much on a synth yet, and just download a lot of virtual instruments via Cubase. Especially with synths, you want to have ALOT of options.
Check out some softsynths from Native Instruments (
www.nativeinstruments.de), Access Virus, Waldorf Microwave, Waldorf PPK, Moog, Nexus,..and oh my..there are so many yet :-)
Most of them are payed named above.. .however, there are a LOT of freeware synths too, and they are very well made (Rob Papen made a few,...fellow member of a dutch forum). etc etc
Save yourself some quid ;-)