I have 2 7250-24P switches and ultimately here's what I ended up doing fan/noise wise.
At stock the switches aren't that bad, but -anything- I could do to make the living room experience more pleasant was worth. Ended up trying a few different fans, and ended up using 2x SuperMicro FAN-0065L4 per switch, which I got on ebay (4 for $30 shipped), these are the Delta FFB0412SHN that might have been mentioned in this thread once.
I live in SE Texas, where the summers get pretty warm, I try to keep the AC at 74 during the day and 72 when the sun starts going down, so consider that to be my "ambient" temp. 23-25c basically. At stock the switches were anywhere between 55-60c, not really that low to justify the fan's noise. As stated, I swapped a bunch of fans but found that if the fans don't move enough air your temps will steadily creep up. I would not use anything under a fan that spins at 5000 RPM (after the 12V current to the fan is ramped down to I believe 4.6~V that is also stated somewhere in this thread?).
Admittedly, these are not that much quieter, but they're close enough in spec to current fans, and run anywhere between 1-1.5k RPM slower than stock (depending on your stock fan revision), that the pitch isn't as annoying and it's honestly quite a bit more tolerable. Temps were around 56-60C idle.
The last thing I did was I purchased some 60x10mm fans as suggested in this thread and strapped them to the ASIC of each with some self tapping screws. Just whatever I had laying around that were the same size. One thing I did that was different was, I had 2 diff 60mm fans since the Sunon wasn't in stock, those being the StarTech 60mm fan that's on amazon for 6.99, and a fan that is identified as model YY6010H12S. The differences between these two are the blade design and the max RPM (4000 vs 3500). To me it doesn't seem to make a difference, I just ordered what I could get quickly so I wasn't spending that much time on this.
Ended up tying those into fan 2 header with a splitter, re-arranged fan pins blah blah. Lastly, I also ended up adding a washer to each screw (I used two screws per fan, cross-wise) which I think made an interesting difference. With the 60mm fans I wasn't really seeing anything great in terms of performance; I gained about 1-2c off my idle which could just be margin of error. After adding the washer my idles dropped to 53-54. Not really sure what the washer is doing here besides maybe preventing the fan from actually trapping turbulent air as a result of being too close? Anyway, figured that was the 'secret sauce' for me, YMMV.
edit: one thing I forgot to add is, it is my opinion that the lack of ventilation on the side closest to the ASIC contributes to temps. I considered cutting a rectangle out and fitting mesh in some fashion but didn't want to spend time doing that at this point. If you really have the time and patience you can just drill in ventilation holes.