Okay... as someone who went through this whole process not too long ago and came out ok, here is my input.
First off, take the SAT. It's easier to study for, and if you know your stuff (which it looks like ya do) you'll do fine. The ACT is useful primarily with Western states, but I don't know of a single school that accepts only the ACT. Both tests suck to take, so just take one. The SAT is something like a 5 hour long test starting at 8 on a Saturday morning. Bleck.
As far as schools go, don't assume automatically that you can get into Harvard and whatnot because they send ya stuff. I got sent stuff by NYU and Stanford way back when, and well, that just wasn't happening. The first thing you have to know about the admissions process is that it is a cash cow for schools. If memory serves, Harvard's application is $80. If they spend 30-40 bucks on mailings and that gets you to apply, then they just made a quick 40 dollars. The Ivy Leagues have something like an average acceptance rate of 13%. No one's a sure thing if their last name isn't Kennedy.
So here's my suggestion: The University of Chicago. I don't know how interested you are in economics, but since you're a Ron Paul supporter, I assume you're at least a fiscal conservative even if you don't have a more defined philosophy yet. The University of Chicago is home to some of the greatest free market minds of today. You would get to take classes from guys like Steven Levitt (author of Freakonomics). It's really cool. UoC is essentially an Iny League school in the midwest, complete with aged building covered in creeping vines. The Political Science program their is fantastic, and it will definitely be more conservative than your typical college.
If you're interested in science, physics especially, you'll be pleased to know that the University of Chicago is also home to the Enrico Fermi lab, named in honor of the first man to split the atom. UoC is one of the top theoretical and experimental physics programs in the country, and there is a ton of research money pumped into the school. Even as an undergrad, you would have the opportunity to work in a research setting with some of the best minds in the field. Pretty cool.
Also, UoC encourages double majors, and you certainly seem up to the workload, so there's no need for you to decide between science and politics. Chicago emphasizes an idea called "The Life of the Mind" which essentially means that they want you to be a well-rounded student. Your first two years at the school will include what is essentially a general education curriculum on steroids. They have everyone in the school take classes on Western Philosophy, Calculus, Poetry, etc. Everyone reads Thucydides and Plato together. It's pretty spiffy.
Chicago also has a reputation for being more than a bit nerdy, which may or may not suit you. It's not a school where you go to have wild and crazy parties every day of the week. Some students who were disappointed with the absence of drunk and rowdy shindigs call UoC the place "where fun goes to die." If you went to University of Chicago, you'd be going there to learn how to think, not how to drink. I don't know you, so I can't say anything about whether or not it would suit you.
Back in the day, I applied to University of Chicago hoping that my test scores and essays plus extracurriculars would counterbalance my GPA. I dunno if they still have it, but when I applied they had the Uncommon Application. Terrible. Took me forever to complete. 4 essays on strange and esoteric subjects, plus a mind-numbing procedural thingy.
My reason for applying was that I thought it would be really cool to go to class in a room where FA Hayek once lectured, or where Milton Friedman delivered his lessons. It's good to be in an academic environment where the free market and small government are held as good and noble, as opposed to the usual college perception.
So to make a very long story short: You have the grades for the top schools in the nation, but nothing is a shoe-in. To get into the very top tier of schools, it's not enough to have great grades and test scores. You also have to have great extracurricular activities, application essays, etc. With your interests, University of Chicago seems like a fit for you in my mind, and you would have a very good shot at getting in. They have some of the best programs in the nation, with outstanding programs in the sciences, as well as the social sciences. Also, they have one of the best college libraries I've ever seen. Not to mention they're about 10-15k cheaper than the Ivy League. It's hard to go wrong with UoC.
Also, in case I didn't make it clear... University of Chicago rejected me, which is all the more reason to go there.
University of Chicago links:
http://www.uchicago.edu/
http://www.uchicago.edu/admissions/
General College links:
http://www.collegeboard.com/
http://princetonreview.com/college-education.aspx?uidbadge=
