I don't know exactly what they offer in terms of a basic unit but Gaugemaster have an excellent reputattion for back up, warranty etc.
Would this do?
https://railsofsheffield.com/products/gaugemaster-combi-combi-single-track-controller-plug-in-transformer-1-amp?variant=35450598621256¤cy=GBP&utm_source=google&utm_medium=cpc&utm_campaign=google%2Bshopping&gad_source=1&gclid=CjwKCAjwwr6wBhBcEiwAfMEQsypPPP0lJYGCFt4Dt8Ifu0on4G4bgLdSXpxDAYHPoc8clxVnsWqQqBoCf3wQAvD_BwE