I appreciate the heads-up on the PSU. Maybe: Antec EarthWatts Platinum Series EA-550 Platinum 550W, whose 5.5" depth is the same as the old one.
The EA-550 Platinum is a mediocre unit with a mediocre fan, I'd avoid.
In my experience, given the space costraints the best option noise wise is the one you had: a new Antec EarthWatts 380D Bronze with a swapped fan, preferably driven by an external fan controller (I also use the R8 with its ULNA adaptor, the only real alternative being the venerable Nexus, sadly impossible to find in Europe). Obviously, nowadays it's a bit of a looser efficiency wise (but nothing decisive IMHO).
Other proven, viable options look like two SFX units, both semi passive: the Silverstone ST-30SF (V1.0, avoid the V2.0/SX-30SF) 300W 80Plus Bronze, and the Corsair SF600 600W 80Plus Gold; the first one is usually rather cheap and with an high temp rating, the other one is rather expensive (it also need the optional ATX plate) but one of the most advanced units available (the 450W version has a more limited fanless range). BTW, given the short cables, check twice if you may needs extensions.
Second best is probably the Seasonic G-360: solid unit, a tad noisier, a tad more efficient than the 380 with the swapped fan.
There are other 140mm units in the market, but either noise wise or quality wise they're not exactly on par with the quoted PSUs: I'm thinking to the Cooler Master G450M/G550M 80Plus Bronze, to the Cooler Master V450S/V550S Semi Modular 80Plus Gold (EOL), to the Cooler Master V550 Fully Modular 80Plus Gold and eventually to the Corsair CS-450M/CS-550M 80 Plus Gold.
The "recent" SilverStone Strider Platinum ST55F-PT 550W might also be an option, but the Silverstone fan controller on that series often turn out to be rather aggressive when internal temp rises: I have not high temp data on it, so YMMV (moreover it's a mediocre performing and rather expensive unit).