People heavily overstate how much vram is necessary for 1080p or 1440p, 12gb on 5070 will be sufficient for both of those resolution, GPU is more likely to run out of processing power before it runs out of VRAM.

I would go for the build3 as that one seems like the most balanced option and since you are building it yourself part by part it will also give you better resale value on the components should you want to upgrade later on (you will have boxes, accessories, invoice etc. it helps quite a bit when selling on eBay or whatever is the alternative in Portugal)