Condolences to you and your nephew, hope things work out for him.
WRT the car, I think insurance will be the crucial factor, as you seem to have a decent budget.
Something like a UP/Mii/Citigo will certainly fit a 6ft adult and insurance should be low. Not sure it will fit the "street cred" criteria though.
Something like a 1.0/1.2 Peugeot 208 or Renault Clio might fit the bill too.
Good luck.