Got a 1.2e 9n3, wanted to upgrade to electric windows but doing an oem upgrade looks to be very hard, i was wondering if i could instead use an aftermarket electric window conversion kit (off ebay) and wire in to a doorcard with oem switches from a higher spec polo. Would this be possible?

The OEM switches for your model are only switching a low current signal, so they wouldn't last long with an aftermarket motor setup

If your talking about the rear windows there are a few poem kits on German eBay and it includes the wiring which just plugs into a connector that is already there. 

Trying to find them in the uk is very difficult, other then my old one which we bought new and deliberately spec'd them I have not ever seen another 4 door with rear electric Windows. 

Life your talking about the front windows then I am 99% sure the wiring goes up to the Apilar so getting the regulator with wiring and door cards you should just be able to plug it in

It was the fronts im looking to upgrade, i dont think the wiring will be there as the polo s models had a ccm? Which controls the electric windows and central locking. 

In regards to using oem switches, my bro had a mk4 golf that had the conversion done with oem switches which worked with a relay?