Buy new suits. Buy each with two pairs of trousers. Rotate the trousers. This is the only way to get the fabric exactly the same, from the same batch, and to have everything match after a couple of years of wear and cleaning. This is one of the hidden benefits of getting custom suits -- buying an exactly matching second pair of trousers doubles the life and, so, halves the effective cost of the custom work.
My life is an open bar...