Yes definitely more minor-ish to the ear. Playing with some ideas in Cmin, C Mixolydian work well. Now to expand beyond that and another short chord progression to try an make it more into a song.
It's more in the Funk, Scofield MMW sort of feel. Now to determine how to best play it to where a keyboard doesn't overstep the walking bass notes, or only have one instrument play them at a time alternating turns.
Most likely if I can get the keys feeling right, I'll keep the chord stabs on the guitar until I try to do some melody ideas.
If you wanted to approach it in this chord-scale way, well neither C minor nor C Mixolydian convey the entire sound of the chord. The so-called "Mixolydian Blues scale" / "Mixo-Blues scale" is historically a common approach in jazz over this sort of chord,
but I don't think most players who used / use it actually call it that. It's just a Mixolydian with a b3 and b5 added (1-2-b3-3-4-b5-5-6-b7)—a Mixolydian with "blue notes" added.
Alternatively, you could just use a major blues scale and add a b7 (1-2-b3-3-5-6-b7), which would be extremely simple to figure out on guitar without worrying much about learning new shapes.
Both of these approaches would encourage perception of that #9 as a b3 and reinforce a bluesy "major/minor" sound though, which may not be the feel you want. Dropping the natural 2 would help in that regard.
Also, it's useful to remember that a scale is just a horizontal version of a chord. So if you're having trouble figuring out what additional notes besides the chord tones you already have will give the right vibe, try voicing the chord on the piano and keep adding extensions to see what sounds right ("right" meaning what gives you the sound you want in context, not just what sounds good in a vacuum).
For example, if you voice the C7#9, you already have the notes C - E - G - Bb - D# [
*see note below].
Now add an F# on top... how's that? If not that, try an F. But let's say F#.
Now add the next extension... what about an A? If not that, try an Ab. But I think A sounds better.
Okay, so now we have the chord C - E - G - Bb - D# - F# - A.
Fold that down into one octave and we have the scale C - D# - E - F# - G - A - Bb. It's basically the "Mixo-Blues scale" without the natural 2 or 4... but honestly that doesn't really matter haha. It's the "horizontal" version of this chord. You can play all of those notes one at a time, without the underlying chord being played, and it will spell out that harmony.
[
*I am mixing flats and sharps here for clarity in the context of the chord, making sure to highlight the b7 and #2 both, but I would probably spell this a bit differently otherwise]
All that said, I wouldn't approach it this way, not in a funk / fusion sort of context. From my POV, all of this complexity is already contained within viewing the passage as G minor, and then plus the added chord tones over that chord IV7#9 chord (and also thinking about those nice leading tones into the VII!), so I would personally take that approach :) But whatever works, however you get there, is great!
Anyway, I didn't proofread this, so hopefully it makes sense haha. Good luck!