Rae, I realise that you have probably sorted your route and stops out to suit all by now, however I was just taking a look at it (for my own interest) as in some places it passes quite close to home, and thought that from experience locally, Krazy Horse (just north of Bury St Edmunds) might be an interesting lunch stop for you all on the second day. It is very close to your present route and would position you for Bury St Edmunds and the A14 afterward.
When you leave the A11, there are some eight miles of wonderful wooded twisty roads leading to it and the venue itself has tarmac parking, good food and some really interesting bikes to see (they are dealers for Norton, MV, Indian and a few smaller makes).
Obviously just my suggestion and probably too late in the day, however I thought that it was worth mentioning.