Datalogger project

I have a project that I need help with.

I need help selecting the correct Arduino hardware.

I need the following functionality.

Digital input to detect dry contact closure from pulse meters. Modbus RTU Master via RS-485 to read data smart meters. Modbus TCP Master to read data from smart meters. Log data cyclically to .CSV file. allow .CSV file(s) to be read via HTTP or have Arduino act as FTP client and perform an FTP sync to an FTP server. Setup and configuration of Arduino will be via HTTP/HTML. data to be stored on SD card.

From what I can tell, the Arduino boards that have serial are TTL so it seems I may need a TTL to 485 chip. Also seems that I will need Ethernet Shield. Ethernet pro does not seem to have UART??

Future enhancements will be: -support high/low alarm setpoint and notification via SMS or e-mail. -option to provide XML vs. CSV.

I have looked at Rabbit/Digi and Netburner to date. I know both of these platforms will allow me do accomplish the above, but I think still too expensive.

Any help or recommendations are appreciated.