Let's start with who has the stronger stand.
Killer Queen should be stronger than Sticky Fingers, not by a degree to inherently decide the fight, but a degree that is enough to be considered. How do I know this? Well we know Star Platinum has beaten the shit out of Killer Queen as well, so the following scaling should hold true:
Jotaro/SP > Kira/KQ
And we know Koichi has got his ass whooped by Giorno, and even though that was more because of outsmarting, I'm going to consider the two around equal (seeing as how Koichi held back, and Giorno held back out of guilt from stealing his shit). That being said, we know now that the two are close to equal. We also know Kira almost killed Koichi, but shit on him nevertheless. Putting them back into the previous scaling:
Jotaro/SP > Kira/KQ > Koichi/E3 >= Giorno/GE
And now, taking Koichi out because he's unnecessary, and adding Bruno, putting it altogether we can see:
Jotaro/SP > Kira/KQ > Giorno/GE >= Bruno/SF
Why does this hold true? I'll explain the logic one more time, Star Platinum has shit on Killer Queen, Killer Queen has shit on Echoes 3 which should be around equal to Golden Experience, whom won against Sticky Fingers, but should be around equal because he won via smarts, not strength. We also know Golden Experience is considered a weaker punch ghost, being stated to only have around human levels of strength. (Even though this is contradicted, the point and emphasis remains, he's weaker than other punch ghosts.) Therefore through scaling, Killer Queen should be stronger than Sticky Fingers.
Now we have the stronger stand, who has the stronger abilities?
Killer Queen's ability to erase anything it touches is a waaayy better ability than opening holes in objects. Killer Queen can be used both for utility (blowing up barricades, causing a distraction) and pure offense. Sticky Fingers does have more utility in general, but can't be utilized for offense nearly as easily. Both of them cannot use their abilities on other stands. I would normally take SHA into consideration, but it seems comically useless in this fight. SHA goes forward like it normally does, Bruno says some shit like "You seem way too confident in this little car." and opens up a zipper in the floor, gives SHA an ARIARIARI to help encourage it into said zipper, and closes it off. SHA has now just been BFR'd. It can explode all it wants, it's not going to do anything. But...
I'm going to have to say Kira wins regardless. His stand is stronger than Bruno's, and his win condition is just "touch your opponent" or even "set off an explosion large enough". Bruno needs to outsmart him, which is much harder to do, especially considering Kira is very keen and observant.
So I'm definitely voting Kira.