First off, for racing LiFe over LiPo is pointless. They are heavier than LiPo, have more voltage drop under load and do not come with the right kind of capacities for 1/8th use.
The advantages of LiFe are seen in extreme bashing set-ups (monster trucks and speed run cars), where very high burst currents are seen (>200A) as the packs will take that without complaint - just the voltage will drop very low.
The packs also allow a little more abuse than LiPo and have therefore been labelled as 'safer'.
ESCs that will run 4S and won't need a separate BEC or Rx pack include the Castle Creations Mamba Monster, the Tekin RX8, the Hobbywing EZRun ESCs (including the Speed Passion) et al. ESCs that won't - LRP/Nosram 1/8 ESC (SPX8), probably the new Orion.
__________________
|