The problem with the standard SharePoint Multi Lookup Field is that I can't store more that 400-500 values in it because of the certain SPListItem limitations. We need to store at least 1000 lookup values per field, possibly more. I am about to start developing a custom field that stores the values in a database table. This field will be very complicated to develop. So, I've searched on the Interned just in case someone already did similar field in the past and found nothing.
Are there any database-based milti lookup fields you know or heard about?