Well you dont have to take the top off to put the rad in there. The top grill will fit on top of it with no problem and itll look like stock. I have mine sitting on a shelf with a shelf above it so you cant really see it anyway but it doesnt look that bad.
Here is a shot from the side as it sits in my shelf. You cant see the thing but it shows that it wont stick up any. The top grill is off.
Here is one from the front with the grill off and you can see how much clearance you have.
I agree it might look a little off with the top grill off and 2 fans sitting on top of it but just sayin', you can do it.