[RichardJ]

The first image is the bottom of a typical, original style Voltage Regulator. They usually have two wire wound, ceramic resistors on the bottom.
The Solid State Regulator in the second image has no exposed resistors and because it has no relays inside, can easily weigh less the half as much as the original style relay.

Most FLAPS sell the solid state regulator in the neighborhood of $30. The original style regulators sell in the $50 to $70 dollar range or more.
You could put an original DELCO cap on either one, if that's important to you.

Most FLAPS now sell rebuilt 10DN Alternators with a rating of 55 Amps. Summit racing even has one rated at 100 Amps.