I'm wanting to replace the Nervar crankset that came with my Sprite with something more modern and lighter and stronger and without those dang cotter pins.

However, the bottom bracket is the wonderful 26tpi Raleigh. How can I upgrade this? Are there new spindles I could buy that'll fit the original cups? Do I have to spend an arm and a leg to go the Phil Woods' route? How expensive is it to retap the threading?

Also, will modern sidepull brakes work with the Raleigh frame? I've got 27" wheels for it so I'm guessing the new brakes will work but wanted to check before I bought some.