The short answer is no.
A power shower runs off a hot water cylinder; the pump runs between the cylinder and shower and pumps water at high pressure.
A combi boiler doesn't (usually) have a separate hot water cylinder and the shower will run at mains pressure (more or less) straight through the boiler via its own internal pump. You might find no or very little difference in water pressure in the shower depending on which combi you install. Power showers can only be fitted on gravity fed systems. Power showers must be connected to both the hot and cold stored water supplies.