If your BEng is any good and you have an adequate English language qualification, almost certainly you'd be accepted on a British MSc.
You've two choices, either go for a specialist MSc in a particular narrow subject matter (for example, Cranfield) or a general "Aerospace Engineering" MSc (such as Brunel).
For an EU student, the costs would be around £3,000 for a 12-13 month MSc, plus your living costs.
But, don't be afraid of applying for aero jobs with a MechEng degree, apart from a few of the most specialist jobs, most of them will be open to you.
G