Update. Can confirm that the 900X4C works perfectly with the 900X3 procedure
After going through the complete process, you must edit the org.chameleon.Boot.plist file before restarting.
1. Graphics Enabler must = No
<key>GraphicsEnabler</key>
<string>No</string>
2. Add these lines to enable HD4000 (with HDMI)
<key>HD4000PlatformId</key>
<string>2</string>
<key>device-properties</key>
<string>5e0000000100000001000000520000000100000002010c00d041030a000000000101060000027fff04002c0000004100410050004c002c00690067002d0070006c006100740066006f0072006d002d006900640000000800000003006601</string>
So far HDMI works perfectly although I haven't found a setting yet to enable both the laptop screen and the external HDMI to both work at the same time.
Otherwise all good, only real major bit of work is to replace the wifi card as Intel is not supported as the boys have already highlighted.
Good work guys.