I used the Prismatics because I already had them complete with engineering.5D Enhanced Low Power/Hi-Cap would give you more shields for less power than 3A Prismatic, and be a ton lighter.
Resistances mean nothing on an explorer, all collision damage is absolute damage. 3A Prismatic ELP/Hi with 3 class E boosters also isn't giving you 1200MJ absolute shields on a Krait Phantom, it's giving you about 680 even if they were all Heavy Duty/Super Caps. (You'd get about 715 with 5Ds)
That is, however, just overkill. You do not need any better shielding than a standard 5D ELP/Hi-Cap. You would be better off investing in your thrusters so you can control your ship in more environments and not bonk into things as much.
And, using them only cost me 0.14 light years on a max range jump.
Overkill, sure, but we'll worth not having to engineer another module.