Don't buy any mirrorless right now. They aren't quite ready especially for professional use. Always the best gear you can possibly get is best which is the 1DX Mk II at the present. I know it is a huge obstacle to over come I was there at one time. But there is always the used market. Great deal on 1Ds Mk III, Mk IV and even 1DX. The reason for using this grade cameras are they are tough and they will be less likely to let you down. You need redundant too. At some point you will be faced with the dead camera at a wedding! What do you do? You have a blushing bride that is going to quickly become a .............. (you fill in that blank) when she finds out you can't do the shoot. Hopefully, it is just a failing battery or CF/SD card, etc., and you just replace it with a backup. But what if it is the camera? Redundant backups are a must for any serious photographer. Your reputation is paramount.
There is nothing wrong with the Rebel line except durability in a professional setting. I used as many as five of them at certain weddings. Only, for my SECOND SHOOTERS, however. Mostly candids and side shots. The 80D is a great camera, one of my favorites. It's only shortcoming is durability which is better than the Rebel line. The 5 series would be a better next step. Again if new is out of the question look used. You need to make a decision is this a hobby or is it a business. If you make good there will be times you shoot two weddings in a day. Thousands of shoots. Gear you can count on is mandatory.
Now lenses, I would only buy EF lenses and only "L" class. The staple duo EF 24-70mm f/2.8L II USM Lens and EF 70-200mm f/2.8L IS III USM Lens. Yup very expensive but they can be a one time purchase. And, again used is an option as there have been multiple versions of these war horses and all are very tough and very good.
EB
EOS 1DX and 1D Mk IV and less lenses then before!
