Right now the only high density choice for you I see is the Cat6k FXS blade, the part number is WS-X6624-FXS so you would need more than one since each only has 24 ports.
Also, there will be another gateway coming out in the next few months called the VG248 which will have 48 ports and is a single 1RU gateway, but it's not released yet and I don't know what your timeframe is.
I'm not able to access my old voice mail messages all of a sudden. The recording says something like 'the message is currently not available'. This has never happened before in all the years I have been using this system. I have t...