CUDA drivers conflict

I am using a Quadro 2000 for my dual monitor setup in an HP Z420 Workstation (no integrated gpu) and added a Teska K20c to do some computing works.
I need a driver for Windows 10 that suits both cards: When installing CUDA 10.0, the Quadro card driver is disabled because utility installs the latest driver for Tesla K20c only.
I tried every possible option for both drivers and CUDA, nothing seems to work properly when it comes to taking advantage of both devices.

You would need to find a windows 10 driver that corresponded to the CUDA 6/6.5 timeframe, roughly speaking the end of 2012 or 2013. Once you do that, you will be limited to using a very old version of CUDA with this setup (6 or 6.5). If you proceed beyond that point (i.e. into the CUDA 7 timeframe, R352 or higher drivers) you will be in the situation you are now, where the Q2000 doesn’t work.

Basically you need to install a windows 10 driver that is R343 (343.xx) or older. And none of this addresses the idea that windows 10 tries to automatically pick and/or update drivers for you. You would have to turn such mechanisms off. That’s possible, google is your friend.

Since I would recommend not using such an old CUDA version, the recommendation I would have is to get a newer GPU for the display.

Thank you for clarification
So any display GPU with compute capability of 3.5 will work for this case ? What do you suggest as model to get everything working under CUDA Toolkit >=10.0 in the same generation as my budget is definitely limited.
And will a cheap AMD GPU solve the issue of actual conflicts ?

any display GPU of compute capability 3.0 or higher will work, currently. Eventually older GPUs (like 3.x) will get obsoleted, just like the 2.x GPUs did (and 1.x before them)

google will give you all sorts of choices.

gtx1030 should be relatively inexpensive.

I think it should be possible to use an AMD GPU, but I wouldn’t be able to give you advice, instructions or recommendations.

Is there any lifecycle roadmap to get version at which 3.5 will be obselete ?
Geforce GT710 seems to fit into my budget, will that work ?