Speaker connections
Tom,
There is no benefit to biwiring or likely little or no benefit to biamping with your entry level receiver. Any 14 AWG or 12 AWG speaker wire will work fine for the connections.
If you want to experiment with biamping, you could run the receiver in all channel stereo mode and connect the L/R mids and tweets to the Main and Surround speaker outputs. Since the receiver shares a power supply for all amp channels, it will deliver less power into each channel when driving 4 channels then it will driving just 2 channels.