These components are not ...

These components are not detrimental to an RO membrane.  Our experience has shown that ammonia can be removed with an RO at lower pH's (4-6 is best).  A full water chemistry analysis is needed to determine what fouling effect the sulfate or other constituents will have.  Ca, Mg, Sr, and Ba are especially important along with iron.  As mentioned a good RO projection program can help with a list of analytes.  These will tell you what scaling potential you have and if an anti-scalant or other pretreatment will be needed.   Rest assured that the water with ammonia and sulfate can be effectively treated with an RO.  Depending on quality needs down stream treatment for residual ammonia may be needed such as simple softening.  We can help get to a good RO projection program or run the projections for you with some additional analysis information.