Interesting, that 1050Ti has only OpenCL 1.2 support.
What NV card would have OpenCL 2.0 then?...

I'm afraid you won't find a nVidia GPU with anything above OpenCL 1.2 as they stopped any further development to concentrate on CUDA.

You linked to a post about a 780, Please look above where you will see it is Common Knowledge the Kepler CC 3.5 GPUs DO NOT WORK CORRECTLY with anything above CUDA 6.0.
I just went through a Lot of work to Build a CUDA 6.0 App for those GPUs, Nothing Lower than CC 5.0 will be supported in future Apps. If you have a CC 3.5 GPU, use the CUDA 6.0 App, anything higher will give increased Invalids.

The CUDA 6.0 Special App is for the older Kepler CC 3.5 GPUs that might not work well with CUDA 8 and above.

I've been looking over my last build which has the gaussfit fix and it appears to be a little better than the x41p_zi+ build. It still has the pulsefind bug, but it might be worth changing over to the version that has one less bug. The Inconclusives on the Mac running the same source has come down quite a bit. I picked up one of those Highly clocked 1050s and replaced one of the 750Ti cards. The 'spare' 750Ti is running the last build by itself and if it continues to work well I might post the App this weekend. This is the Host I just started with the test App, it had been running two ATI cards and had a low Inconclusive list, http://setiathome.berkeley.edu/results.php?hostid=6906726&offset=80

Oh, for the x41p_zi3k+ build you'll need the CUDA 8.0 Libraries.

So what are the recommendations for a) desktop and b) install version of Ununtu?
What do I need to do to turn the ISO into a bootable USB?

The SoG app is much faster on the current BLC tasks for the most part. The servers send you the appropriate app based on which app has the largest APR rate for your systems. That has been the SoG app for about half a year now. This is the case if you are running stock apps. You have a choice of which app you want to run if you run an Anonymous platform like the Lunatics apps. If you want to run CUDA work again you can either choose to run the Lunatics apps and select CUDA50 or install a Linux platform and run the special Linux CUDA app developed by Petri. His CUDA app absolutely blows any other app out of the water with its processing rate. Tasks that take 30 minutes on the old CUDA50 app or 15 minutes on the SoG app are finished in 90 seconds with the special app.