Double will definately fit in the bottom if you lay it flat, requires some minor modifcation to remove extra drive bay and fan holes. If standing on its side it then how much modding required depends on the make of the rad as some are wider then others. E.g. I'm pretty sure the thermochill PA is slightly to wide to stand on its side in the space available meaning you have to do somthing with the dividing plate or case bottom to give you the required clearance.
A triple may be shoehorned in but it depends heavily on how long your power supply is, but then you can always cut a hole in the back and have part of the psu sticking out the back, or relocate it entirely as someone did in a build on here somewhere.