If your parents are only able to pay 20K total per year(10K for you and 10K for your sister), then you need to focus on applying to schools which will leave you with a price tag of approx. 15Kish max. You are eligible for $5500 in federal loans freshman year, 6500 sophomore year, and 7500, junior and senior year.
Schools which only offer need-based aid will not be affordable for your family. Scrutinize the financial aid/scholarship information on each school’s website. They will state whether there are merit scholarships are available and the amounts. If it only offers need-based aid, move on. If your test scores/gpa are in the top 10-15% for attending students, you would have a a good shot at significant merit aid. Run the net price calculators, too.
Also be aware that merit aid does not usually stack on top of any need-based aid awarded to you, it usually replaces need-based aid you would otherwise be awarded. That $5500 federal loan is also included as meeting your need, and does not offset your family’s efc. You need to focus your attention on schools which offer merit large enough to exceed your need and get you to the price your family can actually pay.
My family was in the same boat, and the situation eliminated many schools from our daughters’ lists. They focused their time on schools which we fairly confident would be affordable with merit aid(one got a full-ride and one got full tuition). It is very time consuming and costly to apply to colleges that you can never actually afford. Many students focus too much of their efforts on applying to schools which their families cannot afford, or they never discuss finances at all until it is too late to evaluate more realistic options. You are ahead of the game in this regard and can focus on having some good options that will meet your academic and financial needs.
Your 32 ACT will get you full tuition at the University of Alabama, as well as other schools.
http://talk.collegeconfidential.com/financial-aid-scholarships/848226-important-links-to-automatic-guaranteed-merit-scholarships.html#latest