I would say the 91% one thats already 2100cp.
The difference in iv distribution is negligible really and imo wouldnt have an impact anywhere near as big as the level difference and the stardust saved if you think about powering up the 1400cp vs the 2100cp.
Vinewhip is good for attack, and the IVs are only slightly lower on it, stuill loeer level than the 2100cp however. A fast move TM in the future on the razor leaf one is an option