Have it done properly.
With my lease car, we use ATS and again its massively variable, the main problem being lack of stock of the tyres which the lease company specify I.e. the cheapest.
The lads in my local ATS are brill and I go in a few days before to check stock and they get authorisation and I go back a few days later and job done in 20 mins or so.
For my own car. I use a small garage locally behind a petrol station who do basic servicing and MOTs, not the cheapest but about average price, reliable, and they straighten my wheels on the lease car for nothing it one of the learners catches a kerb.
Probably best to ask around locally to get recommendations for a good garage.