Between the two choices the OP gave, the pentium/dGPU choice is better. However, I'd say it's due to the GPU, not the CPU. The Pentium is only equal or worse than a quad-core Trinity/Richland chip.
Tom's recommends the 750K over any pentiums.
The point about upgradeability is taken, but I'd go for a Haswell chip in that case, and most people don't upgrade even if they have the option too.
Get an FM2+ board and you can use a Kaveri chip, or possibly whatever comes next.