MSc or MSci? They are very different degrees - the MSc is a 1 year masters normally, the MSci a 4 year integrated undergraduate masters.
Also realistically most natural sciences degrees require at least 2 sciences, and I can't see you would gain a great deal from them with only one science.
I also wouldn't suggest taking 4 such subjects - it's usually only advisable to take 4 subjects if two are maths and further maths, due to the synergy between those. I'd also note language A-levels tend to be considered quite intensive in terms of time commitments so again, not really advisable to do a language as part of a combination of four.
If your interest is archaeology why look at natural sciences courses at all? Why not just look at courses in archaeology and/or archaeological science? There are plenty of such degrees in existence already.