Megatron is not in scale so it be an awkward piece next to mp-10 just a heads up. Also if you are not in WA, it may be a challenge to get one as it is not legally obtainable without firearms blah blah blah...you know the rest.
As for Starscream, I have the Hasbro and I tell you right now, I would trade for the Mp-11 version takara as it a better figure and transformation. but if you on a cheap budget, that will do.