I cant give you numbers, but you will need a rahter large pump I think for the sump, seeing as how it has to pump water upwards a few feet. The lower your sump is in relation to your tank, the larger pump you need. And idfferant brands will work differant went pumping upwards.
i.e. the higher you try and pum the water, the more flow you will lose form the pump, and not all pumps are created equal.
a 250gph pump made from brand y when pumping from a sump 4 ft lower than the main tank to the main tank may only have finaly output of 150gph, whereas the 225gph pump from brand x would, under the same circumstances, put out 175gph.
your gonna need to find someone with a decent amount of experience to tell you