There has been some very good advice in this thread, don't ignore it.
What I would add is stick the SR6 on your MPR and get out and shoot hft with it.
That scope will be far better for hft than the light stream would have been. After maybe a year or 2 you will have arrived at a point where you will know what your strengths and weaknesses are, where you drop most of your points etc. At that time you can then concentrate your equipment and setup to give you the help you need in the areas you most need it.
Eg, scope height, a low scope can make the 15mm's easy with a single aimpoint straight through them, a high scope will reduce the chance of poor long range estimation causing a high or low miss. So scope height can offer a lot of help where you are weakest. But until you have shot for a year or so you wont know where your strengths and weaknesses lie, so get the SR6 on and get out shooting and maybe experiment with a high and low scope setup to see which you score better with.
There have been many victories with both MPR's and SR6's, neither can be dissed for this game!
HFT, for people with only 2 buttucks!
VooDoo TwoTwo The next chapter.