Multiple Merge Joins - Maintain SortKeyPosition??

Hi 

I am trying to join multiple tables to the same source in SSIS 2012 eg.

SELECT source.Columns
      ,dim1.Columns
      ,dim2.Columns
      ,dim3.Columns
      ,dim4.Columns
FROM Source
LEFT JOIN dim1
	ON Source.col1 = dim1.Col1
	AND Source.col2 = dim1.Col2
LEFT JOIN dim2
	ON Source.col1 = dim2.Col1
	AND Source.col2 = dim2.Col2
INNER JOIN dim3
	ON Source.col1 = dim3.Col1
	AND Source.col2 = dim3.Col2
INNER JOIN dim4
	ON Source.col1 = dim4.Col1
	AND Source.col2 = dim4.Col2

How can I implement this in SSIS?  I am sorting in the source and setting the SortKeyPosition however, after the 1st join, it doesn't pass the SortKeyPosition on and I can't see anyway of setting this.  I want to try and avoid multiple sort transforms if I can.

Apologies, I missed a vital piece of the jigsaw - the source is on one server and dim1-dim4 are on a different server otherwise i would use a T-SQL statement as above as the source and not join in SSIS at all

Thanks

Barry