Delta's? Ooof, that's rough. What's the hookup on those? Last Deltas I messed with were 6k and had serious power requirements, essentially psu only on a powered splitter.
If you want to be able to hear yourself think, I'd be using something like Arctic, Prolimatech etc, keep the rpm closer to 900/1k rpm.
Gotta think that's mITX, so is going to be on the desktop, next to the monitor, maybe 3ft from your head ±.
And no, I do not believe that a 2900rpm 38mm fan is only 44db(A), or closer to 50db (53db since there's 2 of them)