the late XE had the ribbed single belt setup, and the early XE had twin v belts setup. as you say, the XE has 6 holes for the crank pulley, so why not try and source an early PAS pump, then you are sorted.
if it's the same layout, and the pas & alt will bolt on ok, then yes, you should be ok - however it's more complex, and there's no guarantee the pas & alt mounts from your old engine will transfer - if they do, and the belt fits, you're set - if they don't, you're better off using the twin V belt setup, which is still the simplest layout of the two, and far easier to setup and work on - the single ww belt goes through an engine mount which is a pain.
up to you - you can take all the bits away with you when you fetch the head and use whatever works best for you.
head is finished, just needs cleaning now, give me a weeks notice and it'll be all ready
Gary, I looked last night and it didnt look like the PAS would fit, but having looked at the EPC they are the same?! so maybe I need a closer look, the alternator, is showing up the same too, but maybe thats coz im looking at the mk3 astra, c20xe parts not mk2?