There's more than one ''Bill'' who might fill the bill if and when Reagan appoints another Supreme Court justice.
Attorney General William French Smith has long been considered a prominent candidate. But a growing favorite among the legal community (whose endorsement is almost a must) is FBI Director William Webster. The former judge has gained great credibility with both sides of the political aisle for his judicious handling of law enforcement matters and has pushed up the stock of his oft-embattered agency. Now he's likely to get what he wants from Congress -- better protection for informants under proposed changes in the Freedom of Information Act.