Back End Admin for On-site Registration and Conference Checkin

The one feature that every event extension is lacking is the ability to use it for check-in and on-site registration at the actual event.

RSEvents is so far one of the closest I've seen to being almost the perfect event registration extension. Next up would be Event Registration Pro by JoomlaShowroom. They almost have the backend set up in the perfect manner but it's missing a few pieces too.

Here's the deal. Once everyone has registered online, come the day of the event, we have a table set up for conference attendees to check-in. They can also pay if needed and register online. The staff working the registration desk, need to be able to accomplish the following:
+ easily add a new registrant to the system
+ quickly search a list of attendees ("subscribers") and click an icon or button in one of the fields that will mark them as checked-in
+ quickly search a list of attendees ("subscribers") and in a payment field in the table select from a drop down list that will set the status of their payment as paid and by what form of payment (i.e. options could be "unpaid" "paid-Online" "paid-Check" "paid-P.O." etc.. this should be customizable)
+ quickly generate an invoice that can be printed and provided to the attendee as a reciept
+ Quickly search a list of attendees and be able to edit the attendee details if needed (i.e. name, organization, etc.)

a few of these options are there, but not as simple to get to. some of this has to be done in the submission list in RsForm (to edit the attendee info) - and then other info in the RsEventsPro.

Seriously, I work a lot of events and having a way to use the application this way would be awesome. As it is now, the data has to be exported and used in Excel or Access at the event.

I would be happy to provide more input on this. I think this would put RsEventsPro above any other conference/event management extension out there.