Does anyone here?

I play both, along with Eb, and Contra.
I only own an Eb, 2 Bb's, an A, and a Bass though. No alto or contra...yet .

I'm a bass clarinet player. I double (kindasorta, occasionally) on soprano. i've also played contrabass in clarinet choir, and messed around on a contra alto, alto, and Eb (just borrowed them from friends who play them, never actually played them in a piece)

I've played Bb soprano since 6th grade (I'm in 9th now), and last week I started playing the alto so I could play it in District Band. I also play the alto sax, so the transition wasn't too bad. But I haven't done anything too major on the alto clarinet yet, mainly just messing around and practicing scales.

Bb from Eb doesn't look bad.

Just add one flat to the key signature, transposing it up a 3rd.

i.e. C to Eb, Bb to F