Go to builders' or wherever. Get 2 of those 3 or 4 meter aluminium/wood flat bars. You can drill and use screws or a pop rivet to fasten the rig structure together. When considering the length of your rig, take care to allocate enough space between GPUs to allow for adequate airflow.
Choose your cards wisely, you gonna have to ROI. Look up the ROI of cards that are of interest, see if you can live with those numbers.
You will not find a BTC motherboard around. Biostar is out of stock at the moment. Less you get one on carbie.
I use Z97 Gaming 5 without issues but please prefer the BTC motherboards.
Assuming you got 6 cards and each card consumes max 300W (you will want to do this as power draw differs for coin algorithms), you'll need 2000W.
Yes, there is no 2000W psu on wootware but you can use these
Power Supply Adapter to combine like 2 1000W psu.
You ideally want to feed your GPUs with power from the 8pin PCIE connectors because the 6pin only delivers 75W. The 8pin will give you 150W.
So the 8pin connector end that is split to connect to the GPU will deliver 300W. The GPU riser will add 75W to the mix, then you can power and overclock a 3090 if you wanna.
The above applies if you have power hungry GPUs. An RX480 for instance can live well with a 6pin connector.
DONOT power your power-hungry GPUs with the Molex connector. Use that for your GPU risers.
GPU risers can be powered with SATA power as well as the 6pin PCIE connectors.
Don't forget a power switch for that rig, you'll be jump-starting with your screw-driver every time.
