Dhawald. I would have suggested ipod nano for you if voice recording is optional for you. For your requirement, Sansa Sandisk e250R is the best choice. Make sure that you get e250R and not e250.
Sandisk sansa e250R : 2GB ($140)
Sandisk sansa e260R : 4GB ($179).
This is the primary competitor for ipod nano. the only difference in above two models is the memory size.
Features:
Digital FM tuner,
on-the-fly FM recording,
voice recording,
comes with Rhapsody player (from Real).
removable battery
****has memory slot and so you can increase the memory upto 2GB.****
Compatible with Rhapsody (from real) online music subscription service and comes with Rhapsody player both on the device and on CD. (you can download unlimited number of songs from rhapsody store if you subscribe to rhapsody online musicstore). Not sure if the store is available in India.
20 hours of battery life.
Sleek, thin design with large 1.8” TFT color screen for easy viewing
*www.sandisk.com/Products/Item(2210)-SDMX4-2048-Sansa_e250R_Rhapsody_2GB_MP3_Player.aspx