Looks good, couple things I'd change, but depends on if you're looking for lowest cost etc:

1. RAM comment made above

2. Power switch is unneeded. Short out connection with screwdriver, then mod BIOS to start automatically on power up, then you can use the switch on the back of the power supply.

3. That's a larger SSD than you need - I have a 60 GB and that's more than I need even.

4. Any reason yuou're going for that specific motherboard? Looks like there are others (like the 19 slot one) available for a similar price on Amazon, then you wouldn't have to mess around with the M.2 slot, you can use 19 through PCIe slots: https://www.pyramidreviews.com/product-reviews/cryptocurrency/mining-rigs/best-motherboard-for-mining-ethereum/
Might be different in your location I guess?

5. Yes, build your own frame out of wood will help save money and improve your ROI time

Question: Where are you sourcing your GPUs from that you can get them at a decent price?!