the higher spec MBA is ~500HKD more expensive ~£40, so pretty negligible. l feel the higher spec MBA would be a better performer. your opinion?
As I explained in a post just yesterday, the additional RAM and the additional hard drive space don't offer much, if any, additional performance, assuming that you aren't working with unusually large files or applications that make an unusually large use of RAM or hard drive space while working.
The M1 MBP is only a tiny bit faster than the M1 MBA, but the MBA will be throttled down due to thermal pressure sooner than the MBP.
So, the higher spec MBA will NOT be a significantly better performer, unless you have very high end needs.
However, the higher spec MBA might be a better choice if you foresee the need for more RAM or more storage space long-term.