ESC are not that related to 'c' gei.... But motor, 1900kv, say for a 1/8 buggy with 4S, 25c / 4000 mah and up should be ok.... 1/8 doesn't draw much amp as SCT or some 1/10 .... So if you hv some 30c (say 5000mah whatever)
Again, high 'C' won't hurt, keep the car with better punch for longer time, and depends how new and performance of your battery la.... I hv some 45c battery, performe not as good as some 20c after a while...
Bit on general, for 1/8 buggy, under 2000kv motor, 100a (25c x 4000 mah) would be ok.
Unless you push to 2650kv, and running big heavy monster truck... Check temperature law...
Set current limited is ok, say 120a, but not a must.... You hv Hotwire already?
