Newer Android phone w 64 gb card, power amp music player, and high end in ear monitors. Klipsch x10 as example.
Key is getting a good music playing program for the phone that won't down sample your iTunes to mp3.
I have 250 albums of cd quality apple lossless on my 3 yr old Droid bionic w 64 g card and friends can't believe how good it sounds.
Poweramp music player costs $4.99 and plays ALAC files with all the album metadata just like iTunes.
My micro sdx cards full but they only cost $45 now, so got two more from amazon.
Works great in gym, cycling as well as syncs up in newer cars so you don't need a cd changer anymore.
I'm waiting for the S4 w 32 g internal memory to drop on price and it will be my new smartphone. I should be able to get 300 albums on it.
Cheaper than iPhone which doesn't have removable memory.