Hi,
WinISD is a free, easy to use modeling program. You can download it
here. Plug in the T/S parameters found
here. A 500W amp will be sufficient, as the driver is rated for 500W RMS. Don't forget that a plate amp is only one option. You could always use a 'regular' amplifier and keep it with your equipment stack. And lastly, a large, ported enclosure will give you deeper extension and higher efficiency than a smaller, sealed enclosure. The "boomy" sound associated with ported enclosures is the result of widespread ignorance, improper placement, and poor subwoofer design.