A source close to West Ham majority owner David Sullivan has revealed what this summer’s transfer splurge means for the future. Whether West Ham make a 10th signing of the summer this week or not, they are widely regarded to have had one of – if not the – best windows in the Premier League. The Hammers are set to decide whether to sign free agent centre-back John Egan or even Joel Matip. That decision must be made by Saturday’s final Premier League squad deadline. The club’s owners have committed to spending £155m on signings this summer. That’s factoring in the inevitable triggering of Jean-C…