First off I have been a frequent reader everyday for years now and I always value people's opinions. With that in mind, I decided to post and see if anyone could offer me some opinions.
I have been saving a couple years now in order to make my transition into FF and accumulate some new gear ! I am currently a paid student photographer for a school newspaper and I shoot a ton of sports along with events. I am lucky enough that our newspaper has a full blown studio that is used for celebrities that come to our school, headshots, magazines we shoot, etc. I have become quite well rounded through shooting all of these events on a weekly basis. I currently am shooting with my own canon 7d, 70-200mm 2.8ii, sigma 50mm 1.4 A, and 24-105mmL for most of these events. While I enjoy shooting sports, I'd say that my passion lies in portraiture/studio work, but i do occasionally wander off for a bit of landscape photography I have saved upwards of 8k specifically for photo gear and I have some hard choices to make in that I have a lot of choices to choose from at this budget :S
I'll summarize some of my thoughts so far
-Either a 5d3/or 5ds/ and/or 7d markii
-Potentially a speedlight lighting kit
-Canon 24-70 f2.8ii
I really appreciate any advice on gear advice or experiences working with certain gear, any insight will help me make a more well informed decision Maybe even sell me on new gear Who knows
So, first, lets look at what you do and what want to do more of:
Sports and Events
You want to do more:
First lets look at what you picked out:
5d3 - great all arounder that is good at everything. Only downside are some quirks like the AF point lighting, lack of user changeable focus screen, and the fact that the sensor has been bested by Canon's cheaper 6D.
5ds - probably will not work for you, as it could potentially have difficulties with low light events and sports
7d2 - best for sports, but not the best for portraiture, studio, or landscape
You did not mention the 6D, but that camera is not great at sports due to the less advanced AF, so probably will not work.
So I would say 5D3 makes most sense as a body if you are getting one body.
If you are getting two bodies, you might want to consider the 6D and the 7D2. That would be tons cheaper than a 5DS/5D3 and 7D2 and let you spend the extra cash on glass. For studio/landscape I would say the 6D is superior to the 5D3 as the sensor is better, and it is more flexible than the 5DS; though 5DS appears to be IQ king at the moment, the 6D is more flexible in low light.
As for lens
-70-200 f/2.8L II - fantastic, keep this one
-24-105mm f/4L - I never really liked this lens, something about its images just does not pop.
-Sigma 50A - like you said, getting one that works properly seems to be a miracle but it is a good piece of glass. But for portraits the 85L II is definitely better.
85L II - this lens is best for shallow DOF and extreme low light portraiture. The AF is slow and it is a fragile lens compared to other Canon lenses so it is not something really meant to be taken out of the studio often. That being said, it looks amazing and 85mm is a better focal length for portraits than 50mm due to reduced perspective distortion. It is up to you if you want to budget this much cash to a lens that is basically only for portraiture. If you do a lot of it, I'd say go for it.
24-70 f/2.8L II this is an amazingly crisp lens. But not as much character as the 85L II (or 50L 1.2) for portraits.How about...
Landscape: 16-35 f/4L IS $1100
General/Events: 24-70 f/2.8L II $2200
Studio/Portraiture: 85L II $1900
Sports: 70-200 f/2.8L II (no cost)
5d3 for all $2300 *or* wait for 5d4 later this year *or* 6D (studio/landscape/events) + 7D2 (sports) if you want two bodies.
600EX-RT Speedlite $550
Leftover $1300 for strobes and light modifiers