Piano Forum

I think a good starting point for this is Mozart and the Alberti bass (try k545).  The left hand stays stationary for the arpeggios, so you can get used to the hand coordination that way.  You could practice your arpeggios as well, starting with a stationary one octave arpeggio in your left hand and with your right hand play the notes of the arpeggio in quarter notes (if you're playing eighths in the left), getting used to the interplay of hands, eventually mixing it up so you play the notes of the arpeggio in different order in the right hand (like C, E, G;  C, G, E; E, C, G; E, G, C; G, C, E; G, E, C), first mastering this and then doing simple chord progressions.
In a lot of repertoire you're going to play arpeggios over more than one octave.  After you've gotten the hang of practicing with a left hand stationary arpeggio pattern, you can try practicing the same way but increasing the left hand's arpeggio to a second octave.  Once you can do this with control and ease, you might want to try some of Field's easier nocturnes.  They are a step towards the Chopin but aren't as chromatic, and there are less polyrhythms.  Last year I learned a couple Field nocturnes and Scriabin's Op. 11 no. 21 (the Scriabin has a very simple right hand which makes it a good piece to learn to play arpeggio accompaniment, but the left hand's arpeggios involve some large stretches that may be uncomfortable if you're not used to left hand arpeggios), and now I can play Chopin's easier arpeggio nocturnes.