I'm not an expert on boilers, but I can tell you what we have.
Ours is a Bosch RD 532 condensing boiler that gives c/heating and hot water in our 3-bed bungalow. It was installed in 2005, and is regularly serviced by British Gas. I was told by a gas engineer that every replacement boiler in England has to be a condensing boiler. It has worked very well, and only had one fault some years ago, when a water release valve had to be replaced, but it wasn't a big problem. The condensate drain pipe originally went through the kitchen wall and drained outside, but the recent bad winters made it freeze up, so we had it rerouted inside the house, so that it now drains into the trap under the kitchen sink. That might be a point for you to consider. Best of luck.