Freewheel/chain

I want to replace my block and chain. On pension now so money is
tight, last years saw the purchase of a triple chainset so new block
and chain are lined up for the coming Spring. Have been looking at the
online stores and frankly there is so much modern stuff I am totally
lost. It was simple in my day, buy new block, buy new chain and there
wasn't the complexity that there is now.

So here is the question - can anyone point me to a 6 speed freewheel
block and the appropriate chain that will run on a 48/38/28?

Cheers.