I plan on mounting a dual 120mm rad and fans ontop of my case as part of my water cooling, but should the rad go directly on the case and the fans ontop pulling air through it , or should the fans go on the case directly and the rad ontop of them so they push air through it? and how will either option affect the strength of the mounting?

also should i just mount it directly to the case top, or should i use a bracket plate, like maby a thicker gage steel or aluminum that i could then attach to a larger area of the top panel for greater strength?

It depends if you plan to make a hole in your case.
Putting the rad on the case and putting fans pushing or pulling trough dosn't seems like a good idea without a hole on the top of the case acting like a blow hole,if you were thinking without the hole thing you have to give the rad a place to intake air trough, like you could raise the whole thing an inch or two from the case top with brackets or just acrylic cubes, that would look cool

ok, well for starters i figured that if i was mounting a rad to the top of my case, i would be cutting a hole through the top, this is why i was woundering about the strength of the case, but the main problem is fans or rad first?

will the setup be in your case or outside?

i was origionaly going to have it outside of the case, but i am seriously considering mounting it inside the case. Which would be more sound?

I would mount the rad on the inside of the case with the fans below it pulling air from the outside and through the rad. Yes, this means they will be blowing in air from the top of your case. It is not that big of a deal, just have all of your other fans exhaust. You need to have cool air on the radiator for best results with the watercooling.