picking the right sub

[sageleo]

currently I'm using a velodyne vrp1000, and my room is 20x12 with a large opening into my dining room. So I'm thinking about making my own sub but could someone recommend and good sub I would mainly use it for HT and I would like the bass to dig down deep. The amp I was thinking is a 300 watt bash amp from partsexpress, is that big enough or should I go to the 500 watt? any and all help is greatly appreciated.
thanks

[G-2]

http://www.svsound.com/

[2michaud]

I gotta put this out there... the velodyne DPS-12 is a great sub. I don't know enough to tell you if it would work for your setup, but I can say that I really like it. :D