the boss katana comes with an interface.
you can always get amp sims later on and use them with the katana.
You can use free amp sims with it to start with.
But you also get the amp, with all the effects and usage possibilities.
12" speaker, boss tone studio, easy plug and play.
I'd think about what I'd need.
If it's certain that it's just home studio, an interface might be the more cost efficient solution.
Besides focusrite, I'd have a look at the universal audio volts, Audient IDs,
Behringer UMC202HD / 204HD and 404HD.
Some of them offering more for less money.
