I would say TLS and LoZ: TP. Those are two where every last bit of clock speed counts. You might just have to accept that they won't quite run at fullspeed with this setup.
This is not apples to apples with your proposed custom rig. It's similar, and a little less expensive. The three biggest factors are 1) lack of overclocking 2) lack of easy expansion (MT is a minitower) 3) Your chosen GPU beats this 8570. In the other column, the i7 4770 is a better general purpose processor than the 4670K (but lacks unlocking to do overclocking). Dell made up the cost with economy of scale and a cheaper GPU in this case. You also didn't have to buy Windows separately (their licensing gives it to them for pennies on the dollar compared to retail) but you'll be scrubbing crap from your system left and right.
Again, that's a good balance between a powerful general purpose PC and something Dolphin specific. It won't do everything that the Dolphin rig will do with current 4.0 software but is arguably a better value.
This is not apples to apples with your proposed custom rig. It's similar, and a little less expensive. The three biggest factors are 1) lack of overclocking 2) lack of easy expansion (MT is a minitower) 3) Your chosen GPU beats this 8570. In the other column, the i7 4770 is a better general purpose processor than the 4670K (but lacks unlocking to do overclocking). Dell made up the cost with economy of scale and a cheaper GPU in this case. You also didn't have to buy Windows separately (their licensing gives it to them for pennies on the dollar compared to retail) but you'll be scrubbing crap from your system left and right.
Again, that's a good balance between a powerful general purpose PC and something Dolphin specific. It won't do everything that the Dolphin rig will do with current 4.0 software but is arguably a better value.