I'm in need of Tele zoom as I have some amazing trips planned this coming year! I will be shooting some wildlife and portraits. I have once owned the 70-200 f4 non is but I'm wanting something faster and with a form of IS. I have been out of the loop recently on the new and the 3rd party lenses which brings me to my question. My budget is around 1k, I would like X0-X00 ish but not limited to that. I would also like some form of stabilization, and would love it if it worked with a t-con but isn't a 100% needed. I know the 70-200 f/2.8 is II is amazing but I'm still on a budget, and I know the mk1 is still great IQ which is what I'm leaning towards but what other option are out there whether it's a sigma, tamron, or something else?
:edit- I will be using it on my 5DC and 1D III