The SM7B + Motu M2 looks like a good combo for desk work in an untreated room.
After watching several videos I'm not a huge fan of the sound compared to the NT1, though. The NT1 just sounds more realistic. But, it would pickup low-level background noise a lot more.
That is precisely the crux. LDCs (or MDCs) will get a nice natural to airy sound with good bass response (including optional proximity effect boost) and low self-noise at a moderate price - an NT1 may be as fancy as most of us may need. (AT2035, NT1 and Sennheiser MK4 are some of my midrange faves for spoken word. All have only a mild treble boost of 2-3 dB.) Their relatively broad cardioid response means the environment has to be right though (PGA27 is one of the few supercardioids).
SDC pencil condensers tend to have a more even pickup pattern and tend to be used where low coloration off-axis is critical (e.g. X-Y array). They may have weak low end and tend to exhibit higher noise levels though, and may be subject to some peculiar midrange colorations you don't come across in side-address condensers. A good one isn't really any cheaper than a good LDC.
Dynamic mics interesting for vocal use generally come in 3 flavors, "voice" (presence boost and not overly present bass to compensate for proximity effect in close-up use), "broadcast" (presence boost and neutral to even boosted lows) and occasionally "WTF". I think it is the inherent raggedness in dynamic driver high-frequency response that makes it hard for them to sound quite as transparent as a good condenser, even if the SM7B tries really hard. Due to fundamental resonance, they basically come with a built-in highpass around 100 Hz - something that on voice may be desirable anyway. They will never be as low-noise as good condensers, but still pretty decent in practice (using them for vocal work up close definitely helps in that regard).
What many of us would want is a (short) shotgun mic, but finding one with even dispersion, flat response and good low end is hard. You're looking at around $300 minimum, and some Deity mic was one of the few I've come across that sounded anywhere near as good as a Sennheiser MKH416 (sounds great, but $1000, yikes).
I wouldn't worry so much about the audio interface part if you still need to acquire one... even a lowly Behringer UMC202HD is hardly a bottleneck for a condenser mic in a spoken word application at home (performance with dynamic mics is quite good, too). In my personal setup, mic and room noise never makes it below the 14-bit level (~84 dB worth of dynamic range) anywhere in the audible spectrum, and that's actually pretty decent. So getting along with (-100 dBFS(A); -5 dBFS) = 95 dB(A) should be feasible. If you're not flat out screaming into the mic, you won't exceed maximum input either.
Should you happen to have an existing clean onboard or soundcard input, a little portable mixer may be another option. Note that the very budget end may not provide a full +48 V phantom power but rather just +15 V (Behringer Xenyx 502 comes to mind).
So you already have an NT-USB? Definitely try Equalizer-APO then (using it for my mic as well... I have one preset for my speakers and another for the mic, both of which are being autoloaded). It's not a bad mic at all but that highs peak, yikes. Overlaying the FR graph from its spec sheet in PEACE should allow you to come up with a decent EQ, assuming that is halfway accurate.