The 5.0 bulb should be fine. I have no problem with my plants. If it looks like its dying give it some Co2. That will bring it back to life until you figure out a good lighting system.
Acrylic or sheet pvc, with plastic nuts, you can buy them at the local hardware store. Should work fine, Just use single nozzles if you want the side. A 2-4 nozzle would be fine on the top.