In terms of the likelihood of available future service/parts, you are better off with Lionel equipment in my view at this time, particularly if you have only TMCC and Legacy locos. Simply put, the future existence of Lionel is a better bet than that of other companies who make power supplies.
If you like conventional control, the ZW-L makes sense, if cost isn't a big issue. On a per watt basis, it's no more expensive than other power supplies that give you conventional control. You could also just go with Lionel Powerhouses alone, as the least expensive way to control these locos, if you are going command mode only.
If you want both conventional and command you could go with Lionel Powerhouses and Legacy Powermasters. A bit more money.
The ZW-L also has the capacity to control locos in conventional mode by remote if you have a cab-1L or Legacy cab-2. So while more expensive than the Powerhouse plus Powermaster combos, it also has some features that go beyond that (handles, aesthetics, meters, etc.)
If you are comfortable with electronics, a reconditioned postwar ZW or other transformers, with TVS(s) installed, is also economical for both conventional and command as has been suggested.
