Does NOT need to sounds like the official dub but you can try to do an impression, at the end of it I will pick the best one. 

Send your voice lines in the AAABBBCCC in one audio file

Since this is an amateur project you don't need great audio quality but it needs to be passable (basically don't just record it on your phone mic) and try make sure there is minimal to no background noise

(Race, gender, ethnicity does not matter)
-this is just for them average joe voices nothing too extreme just background or side character where casting a separate actor each one would be much also those who audition for the other roles can also be selected for side and extra characters