possible contenders for best possible portable rig seem to be:
iPod -- aftermarket LOD --> CLAS -- aftermarket interconnect --> RSA SR-71B -- balanced aftermarket IEM cable --> [custom IEM*]
iPod -- aftermarket LOD --> CLAS -- aftermarket interconnect --> Triad Audio L3 -aftermarket IEM cable - [custom IEM*]
iPod -- aftermarket LOD --> CLAS -- aftermarket interconnect --> [upcoming] Alo Rx MkIII -- balanced aftermarket IEM cable --> [custom IEM*]
+/- iBasso Boomslang 2 between CLAS and amp
* some IEMs considered to be among the best are:
Future Sonics mg6pro
Heir Audio 8.A
Spiral Ears SE-5
Unique Melody Miracle, Merlin
Rooth LS8
Hidition NT-6
Starkey SA-43
Earsonics EM-3 pro, EM-4
JHA 16pro
Ultimate Ears 18
Westone ES5
Aurisonics AS-1b
[i'm sure i'm forgetting some]