Someone may say "over-engineered", but.....
5 runs of 4" EMT, w/4-600's each. Support?
2-1/4" Unistrut, 5' o/c; 3/4" threaded rod, & 3/4" beam clamps to structure i-beams. 4" strut strap (downside) on each pipe, on each strut. (Locktite on the nuts)
WOW! That is a lot of support and I bet it looks great.
On the other hand if you want to get a little closer to what is really needed and still sleep well the Power Strut site has some great information on engineering supports.
Power Strut [This message has been edited by iwire (edited 08-11-2006).]