Southampton have officially announced a transfer deal and now it’s over to West Ham United for their fourth signing of the summer. West Ham and Southampton’s summer transfer business is going to be intrinsically linked. The Saints want Flynn Downes and West Ham want Kyle Walker-Peters. But talks have become protracted and fraught over wide gaps in valuations. Versatility is the key quality West Ham technical director Tim Steidten and new head coach Julen Lopetegui are looking for this summer. One area the Hammers have been looking to strengthen is at full-back. And they don’t come much more ve…