Having them thw same on both sides would be easier to plumb up. The one in the picture looks good but the other one will be pointing oddly straight up. Not sure if the set you are thinking of has the same Outlets as the picture. Block huggers and some turn outs and a few pieces of pipe and the turbo will be hanging off the headers in an afternoon. Stock manifolds may be just as easy but i would think it better to run some headers. Even if they are equal length. I have seen them installed upside down and turn and turned around.
Also the block huggers headers from headman and hooker are cheap all the time. The manifolds may get more costly further down the road. And will give better performance. Turbos will need to be supported either way but less with the cast manifolds.