Are you sure you understand the concept of "C"? You got the part about 120amps continuous correct, but that has almost nothing to do with "25C". The ONLY 25C battery capable of 120amps continuous exactly is going to be composed of 4800mAh cells.
Now, that 120amps continuous figure is good. In order to reach that goal with an 18C battery, you need a capacity of at least 6700mAh (where that pack is rated 18C).
"C" is SO misunderstood and completely overrated. You can have a 40C 2000mah pack but it's not gonna do any good in a MT, "even though it's 40C". However, that pack could work if there are about 10 cells in series