tidy

So, we postponed our England trip to a January 26 departure ( I guess that Boris is going to give an update on that date). We are fully vaccinated and the way I understand it now is that we do not need to test prior to leaving the US, but need to pay for (while in the US) and take a lateral flow test within the first 2 days of our arrival but do not need to isolate while waiting for results (of course isolate if we test positive). We also need to complete the locator form 48 hours prior to our US departure.Lastly, we need to take a viral test 1 day before we return to the US.
We are staying at the Royal Horseguard in London, any recommendations of where to purchase the lateral flow test prior to departing the US and then either go to take it (close by to the hotel) or have it mailed to the hotel.
Then my other question is about the test required before we depart the UK. We will be in the Cotswold then and have a reservation for something the morning the day before we depart. Can we pick up the test while in London and then complete it when we are in the Cotswold?
I hope this makes sense. We feel a bit better about going now since we do not need to isolate while waiting for results and because we should get results soon.