Subwoofer to match my B&W 601s2,CC6s2 and DM600i

Plan on purchasing a new sub in the next few days to replace a worn out athena sub that came with the micra 6. I want to spend less than $500 so the svs pb1000 is on the list but im not sure if I should go ported or sealed. Yamaha new NS-SW300 Subwoofer specks and price make it very attractive but I have not found any reviews on said sub but the price online is $170 less so if it performs I should be able to double up in a few months.
Room is rectangleish 13*40*13*40 with a attached kitchen which takes up roughly half the space, and 10 foot ceilings.
Any suggestions ?