I look forward to hearing the completed piece. 
Do you have any pieces that you consider your best, most finished and polished?
I could be wrong, but I think you’re gonna need to step up from Auxy if you’re aiming for something that could sit next to the Illenium track. Structurally, it’s relatively simple, sure, but even looking purely at the non-vocal elements, Auxy won’t get you close enough to that quality of production.
The sound creation, tweaking, reverb and delays options aren’t of the quality or flexibility you might experience in a pro track production, not to mention the lack of proper mastering options.
(It’s not to ‘do down’ what the small team behind Auxy have achieved. It’s fantastic. But, it’s still not a serious music production tool. Fantastic for sketching and initial development. Possibly unmatched on that aspect, for those who work exclusively in midi/step sequencing.)
There are some impressive things being done by Auxy users, but tracks do still tend to be recognisably ‘Made with Auxy’, at least to my ears.
Even on my best Auxy track, if I was remotely serious about a commercial release, I’d consider it necessary to rebuild and develop it outside of Auxy.
Auxy with support for Audiobus might get you closer, though (nudge, nudge, Lenberg. 
But, as I say, I could be wrong.
(This is the bit where someone tells me that the music for the Illenium track was made entirely in Auxy - and I don’t know what I’m talking about. 
I’d be fine with that. Happy to learn. 