The outputs will be the same for all the interfaces and will drive powered speakers. Don't purchase for your skill level or need you have for your studio today but for where you think you'll be in the near future. You don't say but if you also play live gigs, that would certainly be something I'd factor in to the type of gear I'd purchase. Otherwise, for studio use, calculate the most devices you will have running in any circumstance and determine how many inputs and outputs you may use.

Your list is currently keyboard, iPad, iPhone, ZOOM recorder, etc. all of which could use either two mono channels or a stereo. Then there's mics, and other instruments. You can use these devices without issue on a two channel audio interface but your workflow may benefit having more than one device available at a time.

BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.