Reply to "1996 MTH Rail King - 1113 LP (Proto Sound 1) 4-6-4 NYC Dreyfuss Hudson Steam locomotive"

But if you have a TIU on the layout, the DCS remote will operate the loco in conventional mode.  This will give you walk-around control, plus whistle & bell.  I had a DCS system for several months before I had any PS2 locos.

You say you already have a Z4000 transformer.  There is an MTH device, that includes a remote and a box that plugs into the Z4000, which gives walkaround, bell, whistle control for much less dollars than the DCS.  It was called the 40-4001 system; may now have a new number, and may be hard to find.  If you go to MTH web site and search for that number, it will show several dealers in US who supposedly have them in stock.