DE10-Nano Kit vs DE0-Nano-SoC Kit/Atlas-SoC Kit : Which to procure?

The DE10-Nano kit has a hard memory controller. I don't know if these boards will work for your applications, but unless you don't want the HDMI or are cost-constrained, I would probably go with the higher capacity FPGA on the DE10-Nano. The DE0 has a slightly faster ARM CPU complex than the DE10 (925Mhz vs. 800Mhz).

I am going through the DE10-Nano documentation with my board and it seems pretty straight-forward so far. I have gotten some of the FPGA demonstrations to work, and have compiled/run C code on the board under Linux.