Looking for a new mattress

hi,
do you have a recommendation for a new mattress? my husband and i both weigh around 60-65kg, and prefer to have a firmer mattress.
the most comfortable mattress we had before was a king coil pocket sprung with latex topper when we were overseas, but we cant seem to find any king coil providers in the UK. can you please advise what you think would be suitable?
we are looking for a superking, and also preferably we wont feel each other move on the other side of the bed.
thanks!