My Philips upconverting 3475/37 DVD recorder is fairly quiet. (It's definitely more so than my jet engine Magnavox MRV700 with a VHS recorder.) This is the version of the 3475/37 without a hard drive. I have yet to hear any consumer electronic with a hard drive that isn't noisy.
The Samsung BDP-1500 is a quiet Blu-Ray player and upconverter that has no fan. It is allegedly prone to heat issues.
AFAIK, the only set top DVD players that can play video files off a flash stick are the ones that tend to support DivX. I've never seen a standard DVD player that can play WMV/VC-1, MPEG4/AVC/H.264, RealVideo or even Quicktime files. The DivX logo is fairly common on most DVD players and recorders.
Besides listening to players at Best Buy, another option is to modify the internal fan. Quite a few people have disconnected the internal fans of their devices and replaced them with quieter (and more costly) fans or used a quieter external fan as well.