The playing style is at least as responsible for the gentleness of the sound as any of the effects or the guitar itself. The spacey/shimmery sounds come from the big reverb and maybe chorus.
You can replicate those effects with lots of free or low-priced VSTs. Ableton probably includes reverb, a delay, and chorus plugin, as they're very simple to implement and pretty low overhead.
http://www.metalsucks.net/2011/10/07/rigged-devin-townsends-...
Though at the very end, he says:
"At home, I use a Blues Jr. and a delay pedal. :)"
In terms of software, I'm not sure if reverb VSTs will help for that sound, but I've heard rave reviews for the Valhalla Vintage Verb (and Room Verb). They're $50 each, but often favorably compared with expensive reverbs on professional recordings like the Lexicon 480L. There's a free demo so you can try it out.
Watch some YouTube videos about working with reverb, delay, and other time domain effects, as well as general EQ and mixing techniques, and you can get great results without spending a dime. (Training your ear to recognize good results and getting familiar enough with the tools to achieve the sounds you want can take a lot of practice, though. No YouTube video can hone your taste...you have to listen critically to a lot of great recordings and learn to discern how they were made, by ear.)
Go to a guitar store with a lot of pedals or check out the Knobs videos on youtube. Find one with a long reverb time and a tone control.
This could work too: https://www.eventideaudio.com/products/plugins/pitch-delay-m...