What amp do i need to power this subwoofer?

Underpowering your sub will result in voice coil damage over a lengthy period of time. Over driving your subs with more power than rated will cause more immediate damage included burning out the voice coils, damaging the spider and the cones structural integrity. The answer to your question is to purchase an amp that is simply said "within the range of it's limits". Buy a 275 Watt RMS amp at whatever resistance you desire. If you intend to add an addtional sub, look for an amp that's able to provide the power you want now without bridging, but has the capability to double it's ratings by dropping the load, it'll save you the hle of amp shopping when you upgrade.