The new rules should be that people who post this question have to post a screenshot of their bank account. Kind of funny how everyone who asks this stupid question always has a budget of $5000+. I don't think I've ever seen this question posed by anyone with a reasonable budget or by anyone who have even built a computer.
My advice to OP: Build a computer. Get a case with 8 expansion slots. Get a motherboard with 4x PCI-E x16, and any modern intel processor. Buy a 1000 watt PSU. Once you have that all set up and running, then and only then, buy 2 graphics cards. You will then know if this is something you want to dump $5k into.
$5000 for some people is small money. Seeing how easy it is to mine and make money from it, people are jumping in who haven't even built a PC in their life.