If you plan on making a portable Wii, then you definitely want to go with a 4-layer board. The 4-layers use half the amount of power as the 6-layers, and generate far less heat, as you read. The 2 difficult connections that you are talking about are likely the bluetooth connections. Rather than having easy-to-solder-to vias like on the 6-layers, (for the 4-layers) you have to scratch two traces on the top of the board, then solder your magnet wire to the exposed copper. If you've never done it before, it can be a bit daunting, but if you are slow and careful, you should be A-okay. And if you really can't get it, remember that bluetooth is no longer a requirement to boot once RVLoader is installed. You only need it if you plan on using Wiimotes.
So, in short, use the 4-layer. Far less power consumption, far less heat generation. Bluetooth is that "hard connection," and it's not even necessary for your Wii to boot once RVLoader is installed.
