Thanks for the replies guys....only thing Im unsure of is how can my bags get checked all the way through with different airlines??

Im not sure what to do yet as there is a split opinion here but I'm sure I will work it out.

As for a waste of the points - yes it is only about 200 pounds extra to go EK all the way through (Econ) but I have VS points that will only go to waste by next year and I can go LHR-DXB in Upper with the points so get a bit of luxury on the way out.