The answer to this question would have to be the Astell and Kern produced by the iRiver company.
This player will handle 24bit 192KHz files. The added bonus of this incredible audiophile oriented player is that it will also take an input, sadly not for recording though.
IMPORTANT NOTE: Your FLAC files will also be a factor. EG, if you have selected to FLAC an album etc and not set the sample rate high enough then a player such as the Astell and Kern would be wasted on an inferior sampling.
Any player under the sun is only as good as the source files it has been handed. Ensuring that the file is of maximum recording quality however will ensure you have an amazing audio experience but be warned. If you are used to listening to MP3's at low sampling and high compression rates you will find the Astell and Kern allows you to hear clarity in HD recordings that you may not have heard before. Do not mistake these extra's as an issue, it's literally all the information your ears havn't heard yet due to the lwo quality compression and inferior recordings.
PS. There are still AK100 models out there will be available at very reasonable prices. The AK100 will allow up to 96GB of storage(32Gb internal, plus there's 2 Micro SD slots which can each take 32GB each). The new AK120 model, is practically identical to the AK120 model but will allow up to 192GB of storage(64Gb internal and can take up to 2 64GB micro SD cards).
Edited by Spaceresearcher - 1/14/14 at 2:21am