If you're set on PRR, I've seen some nice K-Line A-5 0-4-0 switchers with and without TMCC on the aftermarket.
There are NW and SW switchers available in PRR.
If you're running traditional (as opposed to scale) as I do, I'm planning my next conventional switcher to be an RMT S-4. It's a bit smaller than the NWs and SWs which seems like a better match for traditional-sized runners like me. The NWs and SWs look OK, but they're pretty close to 1/48 scale.