You do not need 32GB of system RAM for a dedicated mining system. 4GB or 8GB is plenty.
You do not need DDR2 RAM for that motherboard. Look at it again.
You do not need an i7 processor for a dedicated mining rig. A cheap LGA1151 Celeron or Pentium processor will do the job.
I am not sure if you see cryptocurrency mining as a guaranteed get-rich-quick scheme, or if this is a serious for-profit project. You will not make $2000-$3000 per month without a very large initial investment, unless you get very lucky with crypto prices. In that case, you may as well buy and hold whatever crypto you're gambling on.
I agreed, with current coin price and difficulty, you can't earn 2k dollars per month with only 1 mining rig at max of 6gpu. You need at least 4 to 5 mining rigs to achieve your goal.
thanx for ur replay ... but i need to know what GPU models to use ... and what is best and what to coin ETH or XMR ? or z cash ?