as far as quality is concerned both the XLR and USB microphones can be excellent for your purposes. what works best for you depends on a few factors.
generally this
https://www.youtube.com/watch?v=rtlOodL16Tc
USB is plug and play and requires nothing but what comes in the mic box.
USB is typically more price efficient than the same mic in XLR + Mixer
USB is available with or without a headphone jack for listening to your own voice during recording.
USB is more clutter-free since it requires less to work.
XLR allows you to use more expensive mics over $200 and allows a greater selection of microphones
XLR mixers allow manual control over such things as gain, eq, balance (instead of using software)
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remember the at2020usb+ (with heapdhone jack) and at2020usb (without) allow you to get the same sort of sound of the XLR version but in usb. they are a great option for recording (they compete with the yeti).
you could honestly go either way. if you never plan to upgrade to a mic more expensive than $200 i would just stay with usb though if you are thinking you may want to in the future it may be worth going xlr. your choice.