hi i have an old z400 that was literally given to me for free. I want to upgrade it but I don't know if the parts i want would be compatible. After looking around I found out that only certain psu's, cpu's and gpu's are compatible?
here are some quick specs:
CPU
Intel Xeon W3520 @ 2.67GHz 32 °C
Bloomfield 45nm Technology
RAM
8.00GB Dual-Channel DDR3 @ 533MHz
Motherboard
Hewlett-Packard 0B4Ch (CPU0 PROCESSOR) 58 °C
Graphics
2470W (1920x1080@60Hz)
1023MB NVIDIA Quadro 600 (HP) 44 °C
ignore the temperatures i directly copied and pasted from speccy.
So i'm assuming i still have the stock psu which is 475w.
i want to upgrade the graphics card, and the cpu, which means i may have to upgrade the psu as well. maybe even the motherboard 
ive been looking for decent gpu and cpus and i want to upgrade to an i5 4460 and a 750 ti.
i dont know if they are compatible but im sure hoping they are. also ive been looking at this power supply called Delta TDPS-650BB because someone said it could be compatible. idk. should i also get a new fan? 58 °C sounds like a lot for the motherboard.
im very new at this so any help would be greatly appreciated! thanks!