The RMS input ratings are the figures that are important.
Peak or Max ratings are for marketing and are good for nothing else.
So - you've got 2 subs each rated for 300w RMS. Dual 4 Ohm coil configuration.
You can wire those two subs to either 4 Ohm final load like so:
OR
a 1 Ohm final load like so:
So - find yourself an amp that makes around 600w RMS at either 1 or 4 Ohms and you'll be gold. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif