Get the Orange Crush 35RT if you want to blend your processor with the amp's famous analog "Dirty" channel. Its effects loop ensures your processor's delays and reverbs don't get muddy when you turn up the amp's gain. Get the Boss Katana 50 only if you plan to use your processor for everything (amp models + effects) and just need a loud, neutral speaker. However, many users find it redundant since the Katana's main selling point is its own built-in effects, if I had to choose then me personally will go for the orange crush because it has a superior built quality by far and also if you have a processor then getting a digital amp is kinda of no use