What I want to do (and I have searched this site for a solution) is to hide the 'Amount' field on the opportunity object from a profile, but only on a certain opportunity record type. 

For instance, I want to hide the 'Amount' field on all 'Major Gift' opportunity record types from the 'Standard User' profile.  We are a non-profit that has major donors that don't want their data to be seen by the whole org.  I can hide the amount field from the standard user profile, but it is for all record types.

Thanks!
Mike.