Start with two Canon 580EX II flashes. Use one on-camera and one off-camera. Either through the camera or on the master flash, you can control the remote flash either through E-TTL or manual power settings. See if you can become comfortable with manual flash in such a way that you wouldn't need to walk over to the remote flash(es) to adjust power. If so, many of the triggering tools out there would be great. If you're better off using E-TTL, consider a third Canon flash as your B remote. If manual flash is OK, various triggers that only signal "Flash now!" will be OK.