About the FFT: I was very surprised to see 60dB dynamic range on the Keysight at uni because that one also has just an 8-bit ADC. I wonder what trick they pulled there.
High sample rate at 8 bits, convert to a short floating point format (whatever is vector friendly), low-pass filter, M:N decimate, then FFT the decimated record.
The low-pass filter is an averaging function that improves SNR by the inverse square root of the number of samples.