graphic cards and etc to built my own mining rig and I don't want to make any expensive mistake.
Trying to mine Bitcoin with graphic cards is one of the most expensive mistakes you can make. Mining with GPU's died in 2012/13. To mine Bitcoin now you'll need ASIC mining hardware.
I made a mistake when I said "
mining bitcoin". I know that ASIC are better for Bitcoin and GPU's for Ethereum. I'm not sure which one to choose yet.
I think these things below will be worth reading before you start mining with ASIC or GPU rig.
Since you are planning to build solar panels then ASIC is always the best for making a profit compared with the GPU rig.
Read this "
First time/Small miner reference for getting started."
For GPU you need to check this section
https://bitcointalk.org/index.php?board=160.0Tools for profit calculation.
For ASIC:
-
https://www.asicminervalue.com/For GPU
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https://whattomine.com/Actually, even old videos will help you how to build a rig it's not hard to build a rig what you need is a riser to mine on multiple GPU on a single MOBO and enough PSU.
Use youtube to find those guides sample this one
https://www.youtube.com/watch?v=VgSGO8ciG8M