yes the canopies are resting on the tanks, The advantage to building your own canopy is that you can put whatever in it you want, it you want a lumenarc reflector and Vhos or T5s, you can at anytime change what you have. it isnt that you will have less problems with a canopy system, it is just more specially designed for what you want.
I still stick to my idea that for what you personally want from your tank and what you are capable of doing yourself that the aquamedic strip light is best for you. It is plug and play, it is quality, it is sleek and will look good suspended with no canopy. you have to remember you are getting advice from all of us, who pride ourselves on changing equipment. so for us a canopy is a piece of equipment we can always upgrade and tinker with. I dont think you are a tinkeror, and it isnt necessary for a nice tank.