Slow Gear or Swell Effect with Gate in Sonar?

No one?? Really?

Maybe a couple of ways I would attempt to do it. (I'm not an expert, though)
 
1) Use volume automation, with exponential curves instead of linear.  Automation nodes would fall on the snap grid points for it to be beat-matched.
 
2) Use Z3ta's FX processing with an LFO perhaps and curves in the modulation Matrix?  I would really need to look more into this.
 
3) Sidechain Compressor.  Used in dance music all of the time.  Basically, you send (sidechain) a silent beat track to a compressor.  The silent beat track is basically a MIDI kick drum with audio output muted, but it has a 'send' channel to the compressor's sidechain input.  For the kick drum,  you basically program any beat you like, usually it's a straight 4/4-time beat'.  Then you play with the attack and release times of the compressor to get the volume swell that you want.  I think there's a few compressors (I'm certain the Sonitus one is off the top of my head) that have the sidechain input.
 
I would use #1 if it's a long swell (in terms of time), and 2 or 3 if it's rhythmic. 

The Sonitus Gate has a variable attack that can be as long as needed, has a ducking mode and can be sidechained. It's capable of lots of interesting effects.

Any compressor capable of a very fast attack should be able to give you that swoosh effect, if I'm understanding the effect you're after. For example, that heavily-compressed ride cymbal sound in some older Beatles recordings, where you don't hear the initial hit but the wash goes on forever. The Cakewalk percussion strip can do it.

You could also try a transient shaper. I don't like the bundled one, but there are many others to choose from, including the free Dominion from digitalfishphones.

Here's another idea: record a cymbal hit and reverse it, then use the bundled Cyclone sample player to trigger it. If you're using MIDI drums, clone your drum track, delete everything except the cymbals from the clone and use that to trigger Cyclone.

If you have Sonar 8.5 you should have GR3 LE which I'm pretty sure has the modifier effects with it.  There are several ways to get the swell pedal effect with it. 

I've used the Sonitus Gate and it will work but I couldn't get it to work the way I wanted it too, same with using a compressor.

You might also search KVR for a Slow Gear type VST.

Dan