As you're on a tight deadline, I think you should just use the software you are most familiar with and have available.
As for ideas for the flyer, I think best bet is to do some searching (e.g. google) for websites and/or images of other flyers, or even check out the yellow pages just to generate ideas, and then make your own layout/template.
A did a search on a couple of images for flyers, came back with:
http://www.interactivecreations.ca/Images/Flyers/highlinecolor.jpg
http://www.parknfly.ca/images/PnF_Exec_Detail_Flyer_v22.jpg
They aren't great, but hopefully have some ideas to get you started. I'm sure there are hundreds of detailing websites as well that will have some flyer type pages.