The USB scopes don't tend to be highly regarded around here and Dave Jones has done a review on this (I think). There are a lot of reasons, not the least of which is limited features.
HOWEVER, I personally highly regard the Digilent Analog Discovery because I get an entire workbench in a single instrument and as long as I stay within its capability, the results will be outstanding. But it requires reading the manual. You can't measure mains voltages. Likely you can't read higher voltages for PSUs. You can, however, build voltage dividers with a couple of resistors.
https://reference.digilentinc.com/analog_discovery_2:refmanualFor $279, you get a fairly reasonable piece of equipment: 2 channel function generator, 2 channel scope, 16 channel logic analyzer, digital multimeter, dual adjustable power supplies (with very limited current) plus other features that are math based like FFT and a network analyzer (Bode' plots of phase and amplitude versus frequency). You can install the Waveforms software and play with the Demo device just to see what's going on.
I have version 1 but I still bought a DS1054Z because there are times when only a real scope will do. And I'm not tossing my 350 MHz Tek 485.
I'm going to suggest that backing up to a 2 channel scope, a real scope, is a bit of a mistake. It is much easier to diagnose the SPI bus with 3 channels and a 4th channel for the trigger (CS' going low). You really do want to see the relationship between MISO, MOSI, Clk and CS'.
I can toss that Analog Discovery in my PC backpack if I have to go somewhere. Sure, I could get a suitcase to carry the stuff it replaces but it's just not the same.
Your topic is debated endlessly. There are no right answers except the DS1054Z and even that is just another Internet opinion. $400 and you're good to go.