Hi
@andyp64. After retiring from my proper job I owned and ran a bike shop for the thick end of 15 years......
Electric bikes are brilliant things. I have one and use it for local journeys. It has a step through frame which makes it easier to get on and off but it is very stiff and not the most comfortable of rides. As with everything else, in choosing a bike you have to make compromises.
Bromptons are acquired taste. Their upside is that, at least the non electrical versions, folded very small and so were easy to lug about. Their downsides were they are expensive for what they were and contained too many brompton specific parts which were almost impossible to get if needed. I found the ride position uncomfortable and as someone in the trade I thought they were more a triumph of marketing than anything else. I had customers who had them and they thought differently.
My thought for you is to get a reasonably straightforward bike with one of the mainstream electrical drives, Shimano or Bosch. Buy through a local independent bike shop if you can. They will help you through the minefield of getting the bike which that will suit you best. Don't worry too much about brands, all the main stream brands are made in the same factories from the same components and at any given price point differ in colour more than anything else and the colour has little effect on performance. If something is cheaper it is because it is of a lower specification. If somebody tries to tell you otherwise, move on.
Be very wary of the cheap stuff with motors in the wheels. There were some models which I would not touch, even to repair a puncture, for fear of turning a simple job into major expenditure if you had to dismantle the electrics to get the wheel out.
Good luck and good hunting. If you see anything then by all means post a query on here and I can look it up and throw in some comments.