Some great ideas, thanks everyone!!

Here is what I plan to include for mh first kitten packs ..

Kitten vaccination record
Kitten health / worming record
Kitten diet sheet
Kitten insurance documents
Kitten micro-chipping paperwork
Kitten sale agreement
Kitten neuter agreement
Some info from the RSPCA promoting neutering

Bag of the litter they are used to
A couple of wet food pouches
A bag of dry kitten biscuits
Kitten treats
2 Cartons of Kitten Milk
Play ball
Cat teaser toy
Blanket that smells of mummy
Grooming brush
Safety Collar
Vial of Frontline
Kitten bed
Scratching mat
Money off vouchers for food / litter

I got most of the items from ebay at a bulk buy price plus I was very lucky that a local pet shop near me closed down recently and as a result was selling stock at a VERY reduced price so I stocked up!