There is no one correct answer.
However 'one wire' alternator's have disadvantages and in no way fit with the OP's requirement for 'cheap and easy' improvement. A fairly thorough explanation here regarding 'one wire' advantages and disadvantages. Self-exiting alternators: Alternator Bible Tech Article by BillaVista
Links and photos regarding the decent and junky versions of the GE Nighthawk H6024NH Crackedback's Harness