choosing a spindle.

[routercnc]

Since you want to use long tools, don't get the 1.5kW version as it only comes with an ER16 collet and not ER20. That leaves 2.2kW or larger and larger wont really gain anything here so go for the 2.2kW spindle.

Typo through speed typing?! My 1.5kW water cooled spindle came with an ER11 which is max ~7mm or 1/4" collets. 2.2kW is usually ER20 so max ~13mm or 1/2" collets.
I can easily cut any wood with 1.5kW so power is not a problem, but to give best range of cutters I would also suggest 2.2kW water cooled.

Can't remember exact import duty but it was in the range of a few tens of pounds - still good value overall.

Chai trades under the name 'linearmotionbearings2008' on ebay. Good reputation, good communication.

If you go water cooled you'll the you might be asking next about cooling systems. In short nothing special is required so search this forum for methods used. I used a radiator and fan designed for overclocking water cooled PCs, but have discovered through use that this is overkill. Others have just pumped the water to a large metal bucket on the floor and been fine.