As a casual observer posting comments, I would say go to NUS. It is a very reputable university and if you are as good as you say you are, Singapore government would nurture you further after your 1st degree.

I would not exactly call a basic 1st degree investment grade, not even from Ivy league. To get to real investment grade (say....MBA from Harvard?), you need to go further and if you have problem financing your 1st degree, why consider UK?

Like I said, Singapore have money and they are willing to spend those money on talent and if you got your 1st degree with flying color, I am sure you stand a far greater chance of securing further nurturing from Sing government. Free of charge. Like i said, consider NUS as 1st choice instead.

I think may be it is even harder to get into NUS than UCL.

Those are general reputation. Better to look at ranking for the particular course you are interested in.