Kade b

I will look into this thankyou 🙂

You're better off looking at the local classifieds and comparing pricing there. Prices for used rigs vary greatly even from city to city, so any price suggestions you get here will be useless unless they're from the same city as you. 

I am planning of building and selling gaming PC’s and I am woundering if a i5-10400f and a 1660 super would be a good combination?

The 580 may not be the best card around but it’s the one I would recommend to a family member building a budget system and it generally holds up on games with physics because of its pretty decent core count 

Thanks

short answer, yes, the mwe gold is good. in fact 550w is enough for almost any single gpu systems. 

Your mainboard can only hold 4 ram sticks you are ordering 4 packs with 2 sticks each