Optiplex 3040 SFF, CPU, GPU, HDD upgrades

I am going to get a Dell Optiplex 3040 in a couple of weeks so does anyone know if I can upgrade the Intel core i3 6100 from the Dell OptiPlex 3040 to an Intel core i5 6600K, an Intel core i5 6700 or an Intel core i3 8350K? Can I also Upgrade the Hard Drive to 2 Samsung HD502HJ 500GB 3.5" 7200RPM SATA's or 1 Samsung HD103SI F3 1TB 3.5" 7200rpm SATA? Am I also able to put an AMD Radeon R7 240 2GB GPU into it and can I put these into the PC without needing to buy a better power supply?