Mixing Corydoras

I posted a bit ago about my lonely little Julii, I'm trying to get him some friends but I can't find any Julii near me. The only corydoras I've been able to find are peppered, will this be okay for my Julii? He's old, ~6 years. If it's okay to get the peppered corydoras how many should I get? I have a 10 gal with nothing else in it although ideally I would like to have a couple different species. So if anyone has any suggestions of good complimentary speeches to corydoras thats appreciated too!

Edit: thank you everyone!! Looks like I will go pick up some peppered Cory's later this week so my guy can have some friends after they're done isolating :) Cory's are my favorite, they're so entertaining! Does anyone else keep other complimentary species as well, or just cory specific tanks?