you have the right idea to filter incoming RF transient spikes. Caps must be rated for X or Y class voltage , plastic film, X-cap (=Line-line), Y-cap(= line-gnd)
Household power meter internal electrodes only clamp to 6kV slowly with ionization, so it is possible to exceed 1kV rating on 1st stage Cap. before MOV reacts. (depends on dv/dt)
MOV must sustain current from flyback of switched current, which is short, but adds stress to MOV unless choke inserted before, which may be my suggestion.
SO Caps ought to be rated for 3kV across line input before filter, additional snubber is useful.
Line filters are usually design for both ingress and egress, but in this case you are only concerned about ingress pulses.