hey Bet;I think bari sax(Eb) might be written in bass cleft because it overlays with bass trombone.
To transpose Eb instruments-I always found it better to think a minor third down in transposing .If you have a C accompanist a 6 th up or a 1/3 down still puts you in A.
If you want to make your keys sound more "horny" try this: record your keys.Now,transpose your keys to Bb for trumpet/tenor,play the transposed line down.So, you have keys in C;trumpet/tenor in D.
Go back to the transpose button-select Eb and alto sound,play the transposed part in A.So;if you did a stereo recording of the keys,mix the Bb/Eb parts on different channels-you have a 4 channel recording that will sound more "real".
The physical dif will add life since fingers will have different note strike/timing like a real section.