guys in my reef club use the Iwaki pump for there return. My friend has his sump in the basement and the Iwaki has plenty of power to get the water back up to the tank. They say the japanese made pump is quieter then the american made one.
You should either have the tank overflows drill into the tank or get an overflow box if you cant get it drilled. IMO
drilled is better.
What type of lighting are you thinking about. Any idea on sump design?
superskimmer.com will give you ideas on sumps and skimmers. If you got room you can use a fish tank converted into a sump to save money.