Why do you want an 8" sub to handle all that power? The only sub I can think of that truley handles anywhere close to that much is the Kicker 8L7. If I were looking for an 8" driver I'd go with either an RE8 or Tang Band 8".
hmmm...not really sure...juss curious...b/c i see 10" subs 12" subs and 15" subs that handle the same amount of power throughout the model line (brahma's, xxx)...yet then the company's 8 inch models handle very little power...wonder why that is...if the 10" can have the same motor structure as a 15"...why can't the 8 inch have it too...
If someone needs to use an 8, its most likely a size issue. If an 8 had the same motor of a 10~15 in would fall into a large class of woofer than there be no point in useing an 8. If you've good a very small old, you can still get an 8 in it if the motor/magnet is small.
I'm a big Boston fan so I'd say go with the Boston 8.5 woofer. somewhat small and can handle 700 watts.