Bulbasaur-Ivysaur-Venasaur.

I have maxed a Vaporeon slayer (Venasaur).
It have now the best moveset for attacking (Vine-Solar Beam). IV 84%.
Now I have around 150 candies. And Im planing maybe to spent some candies and maybe dust in a next venasaur, with the probabilities of having bad moveset. My plan is only for attacing vapes (I have I saur, 2 exxegcutes and one tangela, but I use tangela most to prestige). I can catch 1-3 bulbasaurs per week. (4-12 candies).
My candidates:
Bulbasaur: LVL 4, 97% IV (The best iv but the worst level by far).
Bulbasaur: LVL 20, 88.8% IV (The perfect mixup between lvl and IV.
Bulbasaur: LVL 26, 86,6% IV (Less dust and candies, but only 2% better than my actual Venasaur).
Ivysaur: LVL 20, 86,6% IV (Less evolve candies, more dust than the past bulbasaur).

Or should I stay with my regular 84,4% Venasaur with perfect attacking moveset.
Btw (my ivysaur have razor leaf, so I cant use it for prestiging).