How do you convert/transcode c100 and c300 footage to play/edit in Sony Vegas Pro?

You should be able to use the clips from those cameras directly on the Vegas Pro timeline...
No need to convert before editing...

Sorry! I might gave you wrong answer..

Transfer/Import Canon EOS C300 1080i MXF to Sony Vegas Pro (http://www.brorsoft.com/how-to/import-c300-mxf-sony-vegas-pro.html)

Use the export function in the Canon XF utility. It will move all the mxf into one folder for easy editing within Vegas. You have to do it from the original card. If you forgot to then you will have to access one mxf in every folder!

Canon U.S.A. : Professional Imaging Products : EOS C300 (http://usa.canon.com/cusa/professional/products/professional_cameras/cinema_eos_cameras/eos_c300?selectedName=DriversAndSoftware)

Export is the way to go. You get to rename and add sequential numbering to each clip. Makes for a much more useable file system for future reference. No duplicate file names. Each clip can relate to your project.

i.e. 2013_Foobar_cam1_001

I can't imagine it getting any easier.

Write to your RAID 1 array, copy the file structure when done to a USB3.0 drive and take to your local offsite storage. Done.