Yes, the heatsink sorry forgot to explain, with 10w leds you need a pretty decent heatsink to dissapate the heat, If you look and the ecoxotics the stunner strips dont have a really noticeable heatsink but the panorama pros do, this is because the actual part or the led that emits the light is pretty small so for its size theres a lot of electricity going through so that generates a good deal of heat, Since the led itself is mostly plastic and silicone it will melt if you dont get rid of that heat so you need a piece of a good heat conducter (like aluminum) to take the heat away from the led itself, The more powerful the led the larger the heatsink you need. The cooler you keep your led, the longer it will last. I use computer thermal paste between the led and the aluminum to help the heat transfer even faster to keep the leds cool.
If you lit one of those 10w leds without a heatsink it would fry itself in less than a minute more than likely. So your heatsink is probably the most important part, and a good heatsink makes you led look better also as its the most visible part and what everyone sees first. So if you use a cheap piece of scrap metal as your heatsink, it may work, but it may shorten the life of your leds and make your diy fixture look like crap.
