RS81 C24s are decent wheels. They're essentially the same as Dura Ace C24s without the lightweight Dura Ace hub (i.e steel freehub and axle instead of titanium and alu). However, the design is quite dated now in that the rim is internally narrower (14.9mm) than the current fashion (18mm+), and the low spoke count of 16F/20R may be a cause for concern for heavier/stronger riders.
Shimano make the quietest hubs AFAIK, but their options for handbuilt wheels are limited to 32 or 36 holes except for the expensive Dura Ace hubs, which you can get in 24-36 hole options, and the factory built options all have narrow rims and low spoke counts.
If the OP doesn't mind low spoke count or narrow rims then RS81 C24s or Ultegra 6800 might fit the bill. Otherwise, perhaps a set of 24F/28H rear Dura Ace hand builts may just be within budget, especially with cheaper rims like the DT Swiss R460s. Mavic Open Pro UST or Kinlin XR22T or Kinlin XR31T rims are also worth considering. With a bigger budget, HED Belgium Plus would be a great choice.