Looking to buy a VW Transporter

I am looking to buy a VW Transporter with the following criteria

Must be
Automatic
ULEZ Compliant
2 sliding doors and tailgate
White, Black , Grey in colour
Under £24k

The vehicle will be used for family days out only ie to the beach, national trust sites etc.

Would it be cheaper to buy a panel van and convert it to a 5 seater or buy a combi , shuttle instead ?

What version should I avoid and which ones should I look at buying ? BiTD ?

Buy from a main dealer or private seller ?