The pipe used is 4 inches, that's what I could get easily without buying 20 feet long pipe! My next one will be 8 inches. Epoxy was used only on the screws passing through the pipe (for the little iron angles). The 8 inche pipe that I will get will be SCH80 so plenty of meat to screw in without going through.
The motor is higher than the pipe body, but once siphon starts, it gets filled completely, submerging the pump. The pump I used is a Maxi-jet 1200 powerhead. It seriously isn't the best pump since powerhead aren't good with head pressure. I used it because of the size of the pipe; it was the only one that would fit right inside the 4inch pipe. A real pump would be alot better.
BTW. I'm from Montreal, but now live on South shore. Still work in Montreal though; those bridges are a pain!!!