Hi Takiyaki,
My only feedback here would be you will easily be able to run 30c tyres on the 168. I'm running 28c on wide rims (30mm external / 24mm internal) which measure 31mm once inflated and there is a lot of room both front and rear to spare.
I've put 6,000km's on my 168 and it's been great, zero issues and lovely to ride however I've no experience with the Dengfu so can't give a comparison.
Good luck with your decision!
Olie