I recently bought a 2.2kW spindle + VFD from Chai (ebay: linearmotionbearings2008) as part of a larger order. I've not had a chance to fire it up yet but it came well packaged and all appears to be in order. The price came out to be a few pounds more than the cheapest I could find but I found a number of very bad reviews for the cheapest seller (things not turning up, etc). From what I've read the spindles are normally ok, they all claim Japanese / German bearings but it's luck if they are. The standard VFD's are also normally ok but they seem to vary in quality more although I think the quality has improved a lot in recent years, it seems they either last for ever or go pop in the first few weeks.