If you are planning to your dc going to a uk university it’s not worth it.
international fees are three or four times Uk fees. Most people go to a lot of effort to try to get Uk fee status as it saves so much money.
usually that is three years residency before hand.
the ages of your children are also an issue. Your 16 year old will presumably have done GCSEs and be moving into a levels.
interanational schools vary in the curriculum they offer - some offer IB, some offer American, etc. you’d need to try to get your children into a British curriculum international school which would be expensive (it would be private).
the state system in the Middle East doesn’t generally take expat kids and you wouldn’t want them in it anyway - teaching is generally not in English and it’s a totally different culture.
you might get them into Singapore state schools but be aware that Singapore has the grammar system and children are separated into the equivalent of grammar and secondary modern. Again it is a very different culture and you’d struggle to get them places in a good local state schools.
most expats in Singapore use international private schools which are not cheap.
so yes, you could. You’d be looking at private school fees for both of them for the rest of their schooling plus international fees for uni. Wrong side of 150k at least.