HI, what would you suggest traveling from HK airport to Shenzhen and from there to GZ

HK airport to Shenzhen: There is ferry from HK airport to SZ airport, about 45 minutes and HKD230; there are also coaches from HK airport to Shenzhen downtown, 2 hours and HKD180.

Shenzhen to Guangzhou: There are bullet trains from both Shenzhen railway station and shenzhen north railway station. Duration is about 1.5 hrs and ticket fare for a first class is less than CNY100.