Yes - we only use genuine parts. Most of the time we use good condition used parts to keep costs down for our customers.
We only cover Essex/London/Hertfordshire/Kent.
You would need to make your own enquiries with your warranty providers as they would be best suited to answer that question.
Our view is that we only use genuine parts and dealership diagnostics to carry out our retrofits and activations. The manufacturers state on the warranty page of their website that to void a warranty you would need to make a modification that is not within their specifications and we only stick to modifications that are within their specifications.
Ultimately, it would be a decision for you to make based on your own enquiries and the information provided above.