As others said, M&B2:B launch hasn't even been precisely announced yet, so you'll better wait for AMD to release more of its new CPU, GPU and APU range.
Besides a powerful CPU, to play that kind of game with the highest possible number of NPCs and other active items, you'll need enough RAM, at least 16GB should be enough for now, but leave enough free memory slot to add more RAM later, if needed. If you ever think you'll need more RAM, if you don't need it immediately, buy it later to pay it less, but make sure to buy it before it goes out of production, as from then on the price of higher quality types will only increase, only the cheapest and most mass produced modules will remain cheap for a long time before becoming rare and expensive items.
HW requirements are predicted to be not excessive, anyway http://www.game-debate.com/games/index.php?g_id=4517&game=Mount%20and%20Blade%202:%20Bannerlord , but Windows is a memory hog, and you cannot turn some utilities like antimalware off when you play, if you want to stay safe (but you can enable "game mode" on them to minimise non gaming-related data traffic when you play, and this firewall function could actually make PC performances more regular), so don't trust that 8GB requirement (let alone those 4GB minimum requirements, I have 4GB on my current 8yrs old desktop PC and they are few even for relatively old games), 16GB is a safer choice.







