Sorry to be a bit off topic... but those two should be reversed in my opinion.... hundereds of dollars and thousands of hours...
Good luck on your training, read through the boards, use the search function on this site and you'll do fine... I don't know much about Americorps, but you would probably get better experience with an EMS agency doing clinical work in the field.
Don't know about Chicago, but I am in a suburb of DC and we are a fire/ems department. All career folk are a minimum of Fire/EMT-B, all volunteers are a minimum EMT-B... to be a Fire Fighter, you must have EMT-B though which I support. It works for us, and I like it a lot. Those who are happy doing both, can do both in the same department, yet those who want to do EMS only, are 100% supported as well.
Good luck on everything!