Jamman mentioned the Roland FP30x and Diki says that Roland does a great job with its "piano style" chord recognition. I would like to add that two recently discontinued Rolands-- FP-50 and FP-80 stand up pretty well to the Korg Havian as a piano-based arranger. They can play any Roland styles, in some respects better than Roland's arrangers do! Weight is about the same as your Havian. They don't have on-board style creation. Not sure about a sequencer, etc., but it sounds like you don't need either of these features for your intended purpose. Unfortunately, in the transition to the (current) successor model FP-90, Roland moved the arranger functions "out-board" to an iPad app :-( So if I had any piano chops, I would be looking for the FP-50 or FP-80.