I took a 1975 Viscount and put a 3-speed fixed gear hub on it. Total weight was about 23 pounds. I decided I didn't need 3 speeds for that type of rising, so I sold the hub and made the bike a one-speed fixed gear.
Raleigh bought most other English bike companies in 1960, and thereafter, they made sure that the finest model had the name Raleigh on it. As @
wahoonc says, some brands may have been nicer, such as Hercules or Philips, but that was before 1960. My favorite is the Rudge.
If you want something lighter or spritelier, you need to build it. Be careful, though, because you pretty much have it already in your Motobécane, except it has derailleurs. You could try building a 3-speed wheel for it. But for spritely riding, I prefer derailleurs. Big gaps between gears call for slower riding. And of course, IGHs are heavy.
If you want to build a new bike with a 3-speed, look for a Raleigh International frame or something similar. It has a so-called sport-touring geometry, which is the kind you can ride all day slow or fast. It's a great platform for all kinds of builds. But no one made a sub-30 pound 3-speed, as far as I know.