Re: VST vs Module vs Anything else
I own a TD-9KX and also Addictive Drums but when I just want to practice - what I'm using my E-kit for mostly - I usually just switch on my TD-9 and play. It's faster, a few less proceedings and I don't have to keep switching between the PC and TD to switch kits. The lesser audio quality is not that important to me while practicing.
Keep in mind though that you would need a module (or something like a MegaDrum) anyway to hook up the pads, kick and cymbal. You cannot connect them directly to an audio interface. So you could first get the E-kit first and later switch to using VSTs, just check the module has a MIDI out port.
A kit: Gretsch Renown
E kit: TD-9KX
Masterwork cymbals...Guru snare