The Dire Straits Experience

[Timppa]

Hi,

I have never in my life been to a concert, and the idea of being a photographer there, never really crossed my mind.

I have a contact who works with the Dire Straits Experience, and there is a chance I could get a press pass to take photographs close by.
This overwhelmed me a bit, but it also made me really excited to get this opportunity.
Now the issue is, I don't have the gear, nor the money to invest for this 1-time event, But I don't want to go there with my 'for this job' worthless equipment (a Tamron 16-300 and a Nikon 200-500...)
It will be dark, because it is inside.
I was thinking to just get some borrowed gear if possible.
The items that came into mind would be a D810 + 50mm 1.4 (or 1.8) + 70-200 2.8 (because I don't know how close/far I will be).
I still have a couple of months to read and learn, maybe go to a small venue to try in advance.

What are your opinions?
I currently use a D7100, so another idea was just to get a sigma 50-100 1.8 for example.

Thanks in advance!