How do I create power ups for Autojump game

Hello,

I'm working on an autojump game MegaJump style, where you don't jump off platforms but instead pick up coins to give you a jump boost. I've figured out how to get different coins (with different values), but I'm stuck at how to implement power ups. I started off thinking I would just set one frame (or animation) of the coin sprite to be a power up, and then use choose() to make them appear way less than the usual coins.. Is this the best way to do it? Or is there a way better solution for me to regulate the amount of power ups that will show?

Thanks in advance!

I use the choose method in my space shooter (in my sig) when the supply ship comes it does a random(choose 1,2,3,4,5,6,7,8,9,10) and on 1,2,3,4 you get a heal power-up, 5,6,7 a shield power-up, 8,9 a weapon upgrade power-up, and on 10 a +1 life power-up... it works swimmingly.