Best shield?

[RailNomad]

What is the optimal shield if you craft one? Consisting of two good quality high frequency modulators and shield capacitor? Or should I use medium frequency modulator as the second modulator? I guess shield capacity is more important than the shielding value since the shield takes all the damage without any resistances and it won't last many turns in any case.

[UnLimiTeD]

Generally, a High Cap Modulator is seen as the best choice.
I personally prefer to take the medium route, to protect somewhat against crossbow bolts and the like.
It depends on what your goal is.
If you have armour with really high thresholds, having a weak shield can be a boon, as it only needs to stop enough damage that the rest bounces off your hide.
For a PSI char, even a Capacitor looks attractive if you pick tranquillity, as in uncharted territory it can pay off to just leave the shield on while exploring.
So, what is your aim?

[RailNomad]

I chose the high capacitor too for my assault rifle build with two high frequency modulators. Shield capacity 1022! Though a low frequency modulator would possibly have been better since crippling strikes are the ones that hurt me most.