There are a few extra data fields that we need to store for our customers. (booleans for 'open support case' and 'non-standard pricing', customer number, permanent payment reference number, preferred invoicing method (snail mail / e-mail), and real estate id)
The way I see it, the best way to implement this would be to extend the party model. Is that the sanest option? Also, has anyone done parts of what we need? Especially the customer number seems like something other people might've needed as well.