I'm curious why you are going with a high end motherboard paired with a locked i9 9900? Surely for gaming performance you would be better with an unlocked 9900K for the higher clocks?
To be honest vs a vanilla 9900 I think you would be better off going with AMD. You'll get the same performance for less money and have an upgrade path (current Intel platform is being replaced for 10th gen so no future upgrades on that socket, AMD have 1 generation left in AM4, as well as higher core count cpu's if you need them).
Personally I'd look at an X570 board + Ryzen 7 3700X or 3800X which will give similar performance to the stock 9900 or you could even go with a Ryzen 9 3900X which would give you a nice performance boost if you do any productivity type stuff (the extra cores don't really benefit games, at least for the time being).