Checkout Form

http://rsultimate.com/combat/

I have a few issues and I'm wondering if anyone can assist me.

1) All the levels have an experience value to help calculate the price. However, when a person orders, PayPal writes down the experience instead of the level, since it is the "value." How can I assign two values, etc?

2) When someone clicks confirm account, it makes the form readonly. How can I make it to where when "confirm account" is clicked, the button changes to an "edit form," which would be another image with another onclick value?

3) Notice how there's a list of five items and it asks for how many are true? There each increase the price by a certain percentage, which is their value. How can I make them check boxes instead, and when they are check it inputs their value into the equation?

Any other suggestions let me know, thanks.