[WoW Classic]PC Upgrades for new 8-man team

[Boxen]

Thank you both for your replies. It's very encouraging to have two responses that both agree 100% on how I should approach my upgrade. I'll expand on a few points raised below:

I'm targetting a single 27" 2560x1440 monitor. The main window will be 1920x1080 in the top left corner. The slaves will be 640x360 running along the bottom and down the right-hand edge.

On reflection, I may only run five accounts which would probably be MMMMP. Still undecided but 8 boxing accounts plus my 2 main accounts is a fair lick of cash each month and 8 would also require me to split my accounts over two battle.net accounts which is an extra hassle. Still pondering on that one.

Update: I've ordered the 3900X