What matters for which Apple store you get, is which country you signed up for in the first place. We're stuck (it's okay to be honest as we are between four countries) with Canada, despite living in Austria with office in Slovakia.
If your Apple account is UK-based, a VPN will not help you get US apps. Here's an example. Pandora is only available in the US App Store. We can't download it from the Canadian app store and have no way to download Pandora even with VPN or standing on our heads. Apple wouldn't be able to help us either. We'd have to move our app store to the US. Migrating between stores creates all kinds of havoc and can mean losing paid apps you already have.
The smart companies make their apps available internationally. We can download European banking apps, even from the Canadian store.