Yeah, you can reuse PSU and GPU.
The 5600x consumes up to around 80-100 watts, from the 12v output of the power supply, so it's not like you'd overload the power supply.
The GTX750ti consumes maybe up to 60 watts when you're gaming on it.
Ram will consume 2-3w per stick, usually from 5v, motherboard (chipset, onboard audio, network, usb etc) around 10-15w again mostly from 5v and 3.3v
SSD will consume around 1-2w idle or reading, up to 5-10w when writing a lot of data ... and that's from 3.3v or 5v of your power supply (M.2 connectors are 3.3v only but some motherboards have dc-dc converters producing 3.3v from 5v, for voltage stability and other reasons)
For SSD, I would suggest picking a drive that uses TLC memory (ex Samsung 970 Evo plus, Samsung 980, WD SN570, WD SN770, WD SN850x etc).
Drives with QLC have much lower endurance, and the write speeds decrease if you transfer a lot and fill the write cache - there are some QLC SSDs with very large pseudo-SLC cache like for example Crucial P3 Plus, but most have only up to around 50-100 GB (depending on how much free disk space is