There is an inspection procedure for the oil pump in the factory service manual. If it meets specifications for clearance, and the aluminum housing is not seriously scored, then it is fine.
There were two different oil pumps used in the '90-'05 production series. One was used for all B6/BP Miatas from '90-'00, and then a change was made in '01 when the VVT system was added, presumably to satisfy the extra demand for oil flow. I can't say which one your Protege motor has.
There's really only one choice in genuinely "high performance" oil pumps, and that's boundary engineering.
Actually, boundary have two choices. The first is a set of gears that are dimensionally identical to stock, meant simply to address the problem of the stock gears (which are made by a sinstering process) breaking under high HP loads / high RPM. This gearset drops into a stock '90-'00 oil pump housing.
The second is a set of slightly over-thick gears, intended to increase oil flow, and requires machining to the housing, which is done either on a new stock housing or on an exchange basis.