Sorry for the delayed response. Its been really hectic today.
As a NZ National, you would generally not require a Visa if you were coming to the UK to VISIT. However, you have stated that you will be working in the UK and therefore, you will require a visa before entry.
If you have a job in the UK, for whatever period of time, you will need to apply for Entry Clearance. If you have a job offer and you state that it is for a position under the Tier 5 (Temporary Worker - Creative & Sporting) Category, you will need to apply for Entry Clearance under this category.
The creative and sporting worker category covers people coming to the UK for the purposes of work or to perform as sports-people, entertainers or creative artists for up to a period of 12 months. Entertainers and creative artists may apply to extend their stay to a maximum of 12 months if they continue to work or perform for the same sponsor.
A sports person must be internationally established at the highest level in their sport, and/or their employment must make a significant contribution to the development and running of sport at the highest level in the UK.
For further details of the requirements and application process, click on the following link:
I hope this answers your question. If so, kindly rate the answer and provide feedback.
If you wish to discuss, please feel free to ask further questions.