How do I build the new pipe system?

[sevver]

you can get long sweep 90 bends, they don't really have a sharp angle, they are more rounded and should work well.

[Poconos]

sevver, you're not referring to the drain-waste-vent PVC swept 90's are you? If so they aren't schedule-40 and won't handle the pressure.
Al

[MarkC]

I would use 2 45 degree bends to make up the 90 degree turns. Make sure you buy the fittings that have the deep sockets so the pipe has plenty of area for the bond to occur. Another thing to keep in mind is make sure you plumb in some type of drain fitting in any runs where water would sit when the pump is off. This will help when winterizing.