Are 4-FMA and 4-FA/4-FMP the same substance?

No, these are different substances. 4-FA (also called 4-FMP) is the abbreviation of 4-fluoroamphetamine. 4-FMA is the abbreviation of 4-fluoromethamphetamine! So they are chemically different substances that also have a different effect on you. The molecules are not very different from each other, so the effects are similar. 4-FMA is sometimes sold as 4-FA on the black market. To be sure what is in your powder, have it tested at the testing service!