Building 1st tank helppppp

hi i have this so far



75 gallon tank non reef ready

stand

wet/dry filter

2 hydor 1400 gph



this where i think i got stuck

i bought a eshopps pf 300 i think i should of got a bigger overflow box



is there anyway i can make this work with this overflow problem is the store i bought it i cant return it all sales final



and if i can make it work what brand and size pump would work with it...?



Thanks i need help