Amazon Spain is probably your best option for shipping costs. Any other Amazon store localized in the EU should work. You'll want to avoid the US site. Prices may be cheaper but you may get hit with customs duties and a long hold in customs.
Newegg has a localized Portuguese store. They ship from the US though. The store just lists prices in Euro and adds VAT when you look at the item. I don't know if there are any other import duties from the US. Be careful when looking at parts to choose Newegg as the seller. Many of the hosted third party sellers have bad ratings.
Your build options look good. As far as I can tell you'll have a hard time beating the price.
You'll need a new PSU. That NOX is junk. From what I can find it doesn't have a PCIe connector either. Making it useless for your new build.
The Corsair CXM 550 is the cheapest decent PSU I found. There might be something a little cheaper if you dig through reviews. But this is a model I know off hand. Be careful in selecting a different wattage. There are green letter and black letter units. The black letter are good. The green letter are junk.
I know power prices tend to be high in Europe. You may want to consider an 80+ Gold PSU for greater energy efficiency. This unit also has mildly better build quality.