I saw Oscar at the N Gauge Show this weekend and was very impressed. While it's actually a OO9 model, Kato are selling the motor chassis separately and it looks ideal for making small 0-4-0 N Gauge steam locos. It's fully 12V (so doesn't need a resistor fitting to run) and even has a coupling pocket.

Rails are showing a pre-order for it now. I'd be surprised if Train Trax doesn't have it listed soon too.

https://railsofsheffield.com/blogs/news/kato-announce-new-tool-oo9-gauge-sekisui-range?utm_source=Klaviyo&utm_medium=campaign&utm_campaign=New%20Kato%20OO9%20%2B%20New%20Dapol%20Arrivals&utm_id=01M2NA54WX1WMW0W6X7GYMT1C6&_kx=Nj6KrHKyk7CtkK3-PK5LAD8rrfahh2Q2rxoOpLJmUH4.RXkVMS