You were hypoglycaemic as a communist? Weird. Anyway, they are all physically the same size. Unless you get one of those monstrously big onbes that are some 800W, you will have no problem.
Thats a nice looking PSU that you chose, Antec makes very good stuff. You dont want to cheap out on your PSU, and you didnt. Good work. Antec, OCZ, Thermaltake, and a few other ones make some of the best.