Good news, there are plenty of people on CC who are very familiar with the UK system, as are US universities.
I’m sure you already know that “top 20 schools” are extremely competitive, with pretty much all of them taking less than 15% of applicants, and many taking less than 10%, from very strong, deep pools.
Bad news, needing financial aid + being international makes it extremely difficult. Most take ~13% of their class from international applicants.
=> There are only a tiny number of schools that won’t consider your need for financial aid in deciding whether to accept you: MIT, Harvard, Princeton, Yale, and Amherst.
=> There aren’t many that will meet full need for international students. the 5 above do, and Williams, Swarthmore, Stanford, Davidson, Colgate, Vassar, University of Richmond and Duke all used to (& I think still do, but these things change from time to time); other posters may know of more.
=> Even colleges that say that they will meet your ‘full need’ get to define what that need is: you submit massive amounts of financial info and they make you a financial offer. Sometimes it really does meet your full need- but sometimes it doesn’t.
Your predicted A level grades are strong, and your ECs in the UK context aren’t bad. But tbh from what you have posted, I don’t see anything that is going to make HYP say “wow!”
If you are pretty confident of a top UK choice, and the only reason to go to the US would be if you got into a famous name, then sure- send in a few apps even though the odds are long. On the other hand if you really, truly want to go to the US then expand your list past the ones that you (your parents/teachers/friends) know about, and look for schools where you would be a star.