Norwich is a rather dull place for spotters. The passenger services are operated by Anglia and Central which includes the use of 86/2s on Anglias trains to London. The depot at Crown Point houses 2 shunters and any spare 86s there may be but to stand a chance of seen them catch a train to Diss or Ipswich which pass next to the depot.
The station has several shops and buffet. The city is a short walk away.
A day travel ticket covering Norfolk and Suffolk and now extending to Cambridge costs £9 a day and is the best way to see Norwich , Ipswich and Cambridge.
A long fester at Norwich is bad news as the same few units go round and round (Anglia ones that is)
If going by car and getting a rover ticket then park at Stowmarket at around 0515 and by 0900 you will have seen all the loco hauled Anglia diagrams so then you can concentrate on chasing the units and viewing Ipswich yard.