As I say, Imperial and UCL will just check GCSEs for a 6 in Eng Lang and maths
Cambridge and Oxford will not look at them for shortlisting, but especially at Cambridge, they may be used as part of an holistic decision about offers, but they may well ignore any retake anyway
Imperial, UCL and Oxford do not care about your A levels, either, as long as they are A*AA (with A* in chem or bio for the London unis). Cambridge interview everyone who they think can achieve A*A*A, but again, may use A levels grades as part of their holistic assessment.
BMAT is currently what is used to shortlist for UCL, Imperial and Oxford, provided you meet minimum requirements, though 2023 is the last sitting of this, and you do not get your results until after you apply
Kings do use GCSEs quite heavily, and for an international applicant are probably not a good idea with your grades unless you have a 3300+, B1 UCAT and even then, may be risky
Some med schools use GCSEs in shortlisting and some don't, but your grades look good enough for you to have a fair few med schools to choose from if you get a 7+ in Eng Lang and a high UCAT (>2900).
If you are intending practising in the UK, which med school you attend makes zero difference to your postgrad career prospects, thoug I appreciate this may be different in other countries