I was wondering if anyone responsible for their respective teams unis (jerseys, kits, suits, etc.) has any suggestions for a type of imaging software to use?
Any help is appreciated!
I use Adobe Illustrator. All your graphics will be vector so the Art Department will love you!
Do thumb nail sketches on paper, scan them in as jpeg, gif, tiff. Use them as tracing images in Illustrator.
There are some free programs out there. Here is a link to 20 free programs reviewed.
Or you can hire a pro 
How much would a pro cost? Per hour? Flat rate to design a kit?