All of our paid packages (Sales, Marketing and Complete) have Unlimited custom fields.
You can create both Organisation and Contact custom fields.
When you are adding your organisations and contacts you will be able to populate those custom fields.
If you are dataloading in bulk your organisations (Business dataload) and contacts (Import Contacts) you will see your custom fields to link to on the drop-down menu on the left.
Our Free package has just the one custom field.