While this is a close decision, I prefer a rain team over a sun team. Something that has always bugged me about teams that utilize Harsh Sunlight is that you almost always run a Chlorophyll Grass type, which effectively makes it even more weak to Fire {Dragapult's Fire Blast is a notable Fire move in OU}. I enjoy using a rain team because 4x Fire weaknesses are covered {Scizor and Ferrothorn utilize the rain nicely}.
Onto the pairs you've chosen, I still prefer the rain pair. Barraskewda is insanely fast in the rain, hitting the 700's in Speed {I'll edit in the exact amount of Speed in a bit}. Venusaur is also very good, though it benefits a lot from Growth, which isn't on the set. I would use Stealth Rock on Torkoal, unless this is doubles, which wasn't really mentioned. Pelipper looks good.
While I would personally opt for the rain pairing, both work well. Barraskewda is at a slight disadvantage with all of the Grass types in OU, so Venusaur has that going for it {though there are also quite a few Fire types in DOU}.
Hope this helps! :)
