If you are just looking for a program to play music and that can delete from the hard drive, I use MediaMonkey. It is free and has an option to delete the songs from your hard drive and from the program.
I am using "standard" WIndows Media Player for that. You can delete file from both the library and the file system. As for finding duplicates - sort your library by file size, then scan manually for duplicates. It is one-off task, no need for special app.