Hello neighbor :-)
Both are for your model year PCX, indeed Powerbypcx is quite expensive on some parts. There are parts which are not that bad, and they also offer a 10% forum discount also. I only bought a few aftermarket bits and pieces from them. Bikerzbits seems to be a lot more reasonable on most items - no forum discount though.
Where to buy it fro? It depends if you are planning to use the scooter still this year. The cheap freight option from Thailand, really takes ages - the best I got with land shipping was a miraculous 5 weeks, but 7-9 weeks is more usual. adding customs process to that will mean that the parts are here to put under the Christmas tree. Air freight is bloody expensive but it is at the local customs after about 15 days. Customs are a bit erratic - small boxes sometimes get through with no intervention even is higher than 100 EUR value is claimed on the packet - however larger packets usually held by customs to clear. The headlight is definitely a larger packet.
I'd definitely give Partzilla a chance. The headlight you're after is listed for 195USD (about 175 EUR on current xchange) & they have a flat shipping fee to Slovakia (48USD for shipment value of goods below 200USD ). So far I have received everything from them in less than two weeks. This means that you get the headlight from Partzilla under two week delivered on a price you'd get it from Thailand in two+ moths. I think that's fine.
Too bad, that the body colors don't match up, so you have to source them from Europe. There unfortunately I'm lost. bike-parts-honda.com is bloody expensive, and seems to be down for maintenance for some time now. The other site what I ususally use is
www.motorcyclespareparts.eu, but they only list bikes up until 2013, so our models are not covered - however they were the cheapest option when I have ordered the steering bearings and a few smaller stuff which are cross-compatible and shipping time was an issue.
I went through this with my project bike, so I have a fairly recent experience in ordering parts from abroad. I also do my own servicing so I have a service manual in case you'd need info on torque values or so. Feel free to contact me in PM in case you're stuck.