pump overflow matching

ok, this is probably going to be my new tank. http://op5.triadinet.com/elmers/nlcatalog.asp?loc=nlsearch.asp&args=action|search|searchfor|75A%20Tank|searchby|bydesc looking at tyhe overflow specs, what should my return pump be rated at? maximum flow through of 600gph, using a rated 2400gph...