The Samsung 970 EVO is not a great value. I have a Sabrent Rocket that I like. The 2 TB version is under $300.
Newegg has some 2070 Supers for under $600 that'll outperform the RTX 2060 Super, but it looks like most of the RGB ones like the AORUS are significantly more, so it's up to you.
https://www.amazon.com/CORSAIR-SF600-Modular-Supply-Certified/dp/B01CGI5M24 is pretty good.
SFX is " This form factor is popular with small computer cases and is also often wrongly
referred to as “Micro ATX” power supplies. Because this standard is smaller than
ATX PS/2 in all dimensions, it can be used in cases that support ATX PS/2 with
simple adapters or brackets. Some retail SFX power supplies are sold with adapters
included."