Yes, I've found a lot of horror stories during my research so I am restricting myself to vendors which have had multiple recommendations in reputable forums - and I am buying the latest generation kit with the maker's branding, English language and upgradable firmware. There will still be risks - not least if/when something goes wrong with the kit even though it comes with a warranty - but there are also persuasive reasons for taking that chance. After all, the system is made in China so it should be no different in quality to the same kit which has travelled down the global distribution chain.
I intend to start piecemeal so that any initial problems will warn me off continuing with the bulk of my order. Then I'll come back to you, cap in hand.