Wait until you have earned enough off the second shooter gig to get another 6D, don't get anything "less" in the mean time, it will be wasted money. Though if it is going well I'd suggest get a 5D MkIII next, but not until the photography has paid for it.
Hello. Another option is to use PayPal's Bill me Later. This PayPal service allows you to make a purchase now and have up to or just more than, 6 months to pay. There is no interest if you pay the amount off before the end of the 6 month period. This would solve your problem of not having enough cash to purchase what you need now.
You apply for this at check out at most retailers; Adorama, B & H, or eBay for example. You are approved, if credit worthy, immediately, and only takes a few minutes. If you purchased something today, April 29th, your bill would be due on October 25th, 2014. If you wait until Thursday, May 1st, your bill would not be due until November 25th, 2014.
You can payments to PayPal whenever you wish to pay the amount down. This may be a better option for you. It would allow you to pick up another 6D, new or used, and not have to settle for a inferior crop frame camera; inferior for low light event photography.
Just throwing out another option for you to consider.