Thanks Richard, I'm looking forward to getting it up and going.
My spindle and VFD arrived today. 4kw air cooled purchased through eBay seller solar.jean. I purchased my first spindle through the same seller and have had no issues. I run it 30-40 hours/week in very hot conditions. My warehouse hits 45-50c on hot summer days and have had no issues running an air cooled spindle for 4-5 hours straight in these temperatures.
The new spindle is obviously bigger and heavier than the last but I think the new ball screw z axis and Nema 34 should be able to handle it.
Rory