Which single pilot jet has the largest cabin and longest range?
According to Wikipedia's list of light jets, the longest ranges (for single pilot certified jets) are:


SyberJet SJ30: 2205 NM
Pilatus PC-24: 2035 NM
Embraer Phenom 300: 1936 NM
Cessna Citation CJ4: 1927 NM
Cessna Citation CJ3+: 1825 NM


Sorting by max. number of passengers, we get:


Pilatus PC-24: 8-11
Embraer Phenom 300: 7-10
Cessna Citation: 8-9
SyberJet SJ30: 5-6


Considering you are already rated for the Phenom 300, this is likely your best option. Anything larger will always require a minimum crew of 2.