Welll, unfortunately DreamStation doesn't currently exist as a VST. There's a DXi version (a Micro$oft DirectX soft synth), but you can only get it packaged with Cakewalk's Sonar.
There's a DXi that ships with Synapse Audio's Orion Pro/Platinum that can be made to sound like that demo MP3 (it
did sound nice), but again you'd have to buy that to get the synth...
Not much help here, am I...
Buzz has several synths that can pull off those sound (with appropriate effects afterward, of course), but if you've never used Buzz or don't care for it that will be a problem.
How about Crystal (
http://www.greenoak.com/crystal/ ) or BizuneVST (
http://www.bizune.com )? They're both pretty dynamic. If nothing else, you can cobble together your own with SynthEdit (
http://www.synthedit.com/ ).
Hope that's of some use to you.
*fixed SynthEdit URL (they're using frames...grrr)