Assuming you're using the 4ohm SVC version of the PB10, I'd go with an amp that will produce 300w into a 4ohm load.
If you don't plan on adding another sub, you could get a 2ch amp (rated around 75x2 @4ohms stereo) and run it in bridged mono for around 300x1 @4ohms mono.
Or, you could get a mono sub amp. They're usually stable into 2ohm or lower loads. If you got something like a JBL BP600.1, it would produce 300x1 @4ohms. If you added another 4ohm SVC sub in parallel, it would produce 600x1 @2ohms (each sub would get about 300w).
