Stick with the 5600x as long as you can get it for stock rrp, if you are going to hold for 10 years then you could pick up the 5900 in maybe 5 years time for less than the extra (250.00) it would cost you today i'd imagine. Plus the 5600x is comparable in multi core operations to the 3700x thus suggesting it wont age that too bad. I put a e-sports duo cooler on mine, also got the Tomahawk X570 and its great (quite essential as you will need bios flashback before you can boot the CPU, basically flashing the latest bios to the board without the need for a cpu or graphics card installed, it was fairly easy and worked my end). Personally i wouldnt bother with the sound card, the onboard sound is easily as good as that, but i will say an external DAC (SMSL SD793-II) for around 60.00 is better from experience but certainly not essential at your budget. Ram side, i'm running 3200 ram which is great with the CPU and runs fine on the motherboard, but i'd probably go with 3600 if i was buying now, slight increase in price and a minimal increase in any performance.
