[LAU] Pocket Guitarix?

[Tim]

Hi list.
My needs:

Guitarix
Battery powered
2 Hr or better run time
Pocket sized
For live use
Latency <= 128 frames (at say 44.1Khz)

Are there any pre-built units for this sort of thing
  out there?

If not, I'd take a small embedded board, hopefully
  with enough room for stereo audio jacks, but
  I'll take mono. A midi in jack would be nice.
Any one experienced with this?

What is the state of phones these days
  for real-time audio? Is Guitarix doable?
What about input and output jacks?

Thanks.
Tim.