In order to get their inheritance, I'm planning on caring for my aging parents.
Do you have a plan as to how you're going to get the inheritance?
I'm going to guilt trip them so they see me as a better son.
It is expected to care for your parents not just so that you get money when they die. It would cause problems with your siblings if things are not divided equally. It is better to care for them just because and share with your siblings if you want them in your life.
I'm going to convince my siblings that I'm the best person since I am caring for them more.
Your motivations are immoral and you shouldn't be taking advantage of your elderly parents. I hope you and your siblings will choose to each care for your parents out of love and respect for them, not money.