There is a difference in head loss when the pipe is running horizontal as opposed to verticle. Elbo's and tee's also add to the loss.
Do you plan on using the Blueline pump? If not, there are a bunch of pumps there. Pick what you will use.
Just remember, if your overflow can only handle 600 gph
, don't get a 1200 gph
pump. You must match the pump with the capacity of your overflow.