ohh Nooo. too big of a pump???

[trouble]

was just reading a thread about a guy that bought a really big pump for his 72 gallon. well i have a 72g running on an fx-5(jack ass guy at lfs) and am slowly organizing info and parts to switch over to a sump. recently purchased a 33g sump(thank you very much finn-a-gin), and ordered a supreme mag drive 1200 which will put out between 8-900 gph at about 6'. Now having read that thread am worried i have over done the amount of return flow thus spending more money than i had too. especially considering i am running 2 koralite #3's(850 gph apiece).Any thoughts.

well we're at it was planning a 2" drain with a 1 1/4" return, is that going to be sufficient. And can some one direct me to some info on the kirby style overflow? please thank you