i5 5250u and i7 5557U are mobile based CPU & both are Dual Core.
pentium g3258 vs i3 4360 is desktop based CPU & both are Dual Core but much powerful than mobile based CPU.
For 3d rendering get desktop based CPU.
I would say get a i5-4460+H81 mobo. Even if it will cost more but it will save you in the long run.