You won't be able to buy a PS4 on the Mainland until December, I'm afraid, and as there are only 200,000 units being shipped to a country of more than a billion people, you probably won't be able to find one through traditional means. You're reasonably close to Hong Kong, though, so if you've got the cash and time you could pop over to there for a holiday shop (don't be ashamed - everyone does it). However, this most likely means your PS4 will only play Region A/1 Blu-Ray (same as the US), which could be a pain when you move back to the UK, which is
Region B/2.
You could also look around for technology malls; the ones in Beijing usually have an entire floor dedicated to flogging game consoles and software imported from HK. IIRC, you're in a very affluent part of China, so I'm sure there'll be something similar there, too. There will be a mark-up, though, and the 'buyer beware' maxim kicks in double on the Chinese Mainland, as there's every possibility you'll wind up with a fake, defective or out-of-warranty product.
Regarding region-locking, PS4 games are region-free as standard, though DLC is country-locked (from what I can tell, this means that if your PSN account is registered to country A and the game disc you bought comes from country B, it won't install or work properly... though they'll still charge you for it. There's a workaround
here.) and Blu-Ray discs are region-locked.
BTW, if you're going to buy a laptop, you should do that in HK too. It won't have Mainland spyware or shithouse proprietary software loaded as standard, which happens on the Mainland, and the builds should be sturdier too.
Alternatively, Play Asia is a useful source of games and tech, including
PS4s from the US, Japan, Asia and Europe regions and usually offers multiple regions. However, you'll need a credit or debit card to pay for it, and good luck getting one of those on the Mainland. I'm assuming you're planning on using UK funds to pay for this anyway, mind?
Also, if you're looking to buy a flatscreen telly, it's worth spending a bit extra to get a Western brand (or taking advantage of the Singles Day sales that will be happening tomorrow, November 11). I got a Chinese brand for 1,000RMB less than it would've cost to get a Philips or Panasonic or something, and it was a stupid mistake - the screen blurs something rotten during fast movement, the settings are minimal and I can't seem to get my PC to fit the screen when I connect it via a HDMI cable.