So I have the build mostly figured out.
I am going 16 Strength, 13 Dex, 12 Constitution, 8 Wisdom, 8 Intelligence, 17 Charisma. I am going to start Paladin for the Wisdom saves.
I am going to play a Drow favored of Zinzernia - makes for good thematics with Paladin and Whispers Bard.
I will be getting Persuasion, Athletics, Perception, Stealth and Deception to start with. Expertise first in Deception and Stealth and later in Athletics and Persuasion.
Feats are going to be Drow High Magic at Bard 4 (we get a +1 Charisma with this via houserule), Shadow Touched with Wrathful Smite at Bard 8 (CH19), either Spellfire Spark or Elven Accuracy at level 12 (CH20)
The only things I am undecided on - Should I take any Sorcerer levels. I can pick up 2 level of Sorcerer, probably at level 3 (P1/B1/S1) and level 18 (P1/B15/S2). This delays Psychic Blades scaling by 1 level but gives me Shield and False Life. Innate Sorcerery is twice a day and would give me advantage on spells, including the Truestrike that is my prime attack and landing crits with both psychic blades and divine smite is huge. If I did this I would take Elven Accuracy at Bard 12. This also gives me an Epic Boon a level earlier, but one less feat overall.
Not sure about my Origin Feat yet. I am thinking about Tough, but I am not a huge fan of that feat.
On the Original question - I am going to do Wrathful Smite and Divine Smite until Bard 6, then swap for Searing Smite, then when I pick up WS on the feat at Bard 8 put Divine Smite back in.
Thoughts??