You are correct Kickstarter will only allow you to choose one pledge reward however you are able to change your pledge dollar amount. Add up the amount of the items you would like to add ( you can even shop the website) then increase your pledge dollar amount to represent the total for all the items you desire. Then send us a direct message itemizing your order. We will message you back to confirm that everything is correct.
If you tap on our icon up at the top with our name you will be taken to our profile where you will see the option to send us a message.
Please don't ask questions in the comments section since we cannot directly answer you and we will not be able to reference our conversation as needed in the future.
Don't see the answer to your question? Ask the project creator directly.