HaiPhong to Nanning >>>>>>≥ Nanning to Bijing

1. I want to travel to Nanning,China from HaiPhong, Vietnam using the bus as its cheaper.

I have noticed that there is a bus company called Guangxi Yunde Transportation. Are they reliable and are they comfortable for such long trips? And how much luggage can one carry?
2. Which other way is cheaper to get to Bijing from NN, as it'll be my final destination.

Please do recommend the best ones that are affordable, so long as they don't mount up to a flight ticket. Also schedules with fares included

Thanks in advance.
Rachel Chabalala