I am switching to the Sony A7III and plan to shoot some indoor sport. From what I've read/understand F2.8 can be a tad slow for Indoor sports (depending on lighting) on top of which the Sony 70-200 F2.8 is a little more then I intend to spend at this stage. As such I am seeking a Fast Prime Lens to use, it's usage will be split between Basketball and Portraiture. What focal range would you suggest for these applications, I am tossing up between 85mm, 105mm, and 135mm, leaning towards the 105mm largely due to it being the middle ground. I will be patiently awaiting the Sigma ART range to be released native.