Yes and yes but nobody does it that way. You can get just about any value you want with series/parallel combinations of common power resistors. They would be very expensive and cumbersome. Most high current supplies like you describe would be controlled by a variac on the primary of a large step down transformer or phase control of an SCR/Diode bridge on the secondary. A high current linear supply might have 8 or more 2N3055 NPN transistors (15A,115W) with emitter resistors, in parallel. Huge heat sinks and fans are often used. One or more driver transistors are needed for the relatively low gain outputs. The most common IC for this sort of supply is the LM723. It provides for both voltage regulation and foldback current limiting and has been around for decades.
Is there a maximum amount of ripple that your application can tolerate?
Joe
