It sounds like you're looking for the same thing as the folks on the "best player for audio books" thread.
What I can tell you for sure is that the Sony D-NE500 Walkman MP3 CD player resumes properly with MP3 files, if you don't mind having to burn stuff to a CDR first. I haven't tested it with low-bitrate MP3 files, but I doubt that would be a problem. It displays the ID3 tags; I'm fairly sure it does the fastforward stuff too, but from what I remember seeking was kind of slow.
I am looking for a MP3 player that will play 16-bit MP3 files fairly well (these are very long files.. about 1-4 hours each). The specifications I am looking for include:
1. displaying ID tags
2. has "resume to last point" feature preferably (I am looking into bookmark feature also)
3. will fast forward and rewind while the file is playing (not as necessary)
I have been online for I don't know how many hours trying to find these specs on MP3 players. I guess I just don't know everywhere to look Any help would be appreciated!