flash advice for 7D?
Since you are going to be doing commercial work then you must have reliable equipment, and backups. I happen to think that you are better off with high quality RF triggers like Pocket Wizards than with the 600EX-RT because the PWs can be used with other brands of flash. With the 600EX-RT you are locked into the Canon proprietary RF trigger system. PWs can be used with almost any brand of hot-shoe flash and many brands of studio strobes.
Several Sekonic flash meters even offer a PW trigger as an option and I strongly recommend you buy a good flash meter to help you control the multiple light sources.
My recommendation would be one or more 580EX II flashes with one or more 430EX II for off camera. You may also want to add a number of smaller budget priced optical slave flash units to hide around a room to light selected areas. Another trick is to replace a bulb in a light fixture with a small screw base optical slave studio strobe. Examples of low cost optical slave hot-shoe flash units are.
Don't forget to get some sheets of various colored gels so your flash units can match ambient lighting.
Stands and umbrellas and/or softboxes are nice for giving you a broader fan of light than you get from a bare hot-shoe flash. Don't forget some sand bags for the stands.
Living and loving it in Bangkok, Thailand. Canon 7D - See the gear list for the rest.