SeedsWeeds G'day and welcome, you had me at Led haha
First things first.. Being in Aus... Paying an American distributor for a grow light is costing you an arm and a leg in shipping tax and labour not to mention conversion rate. So building it yourself is going to save alot of money,, and that is the goal right?
Secondly, types of leds..
Starting by grouping anything mass produced in China for the western market all of these leds are designed to be cost effective for the producer, in other words the leds are the oldest cheapest model they can get to work well enough along with all other components In order to be a profitable product even at $150. So they are all going die quicker and put out less than better quality leds.
Next would be mass produced lights that have high end chips in them such as ledhydroponics.com, timber growlights, spectrum king, northern growlights, chillleds along with many others that are mainly western based companies that use the newest components in order to make the best working product they can. These are worth an American consumers money but us lot are substantially upcharged due to no other reason than our location, sucks but is what it is.
Lastly the diy option.. it's simple enough to build the light but that aside the benefit is in the savings you make. You can obtain the leds these high end companies are using and get the same results but far cheaper.
Cob leds are now being outperformed by strips and quantum boards but all three are very user friendly, effective and worth your money but the cobs are the most simple imo. Nothing stopping you from integrating all three.
Check out this site man, Australian based so shipping isn't a massive killer.
http://www.cutter.com.au/categories.php?cat=MAU5+KITS lots of options there, far better than anything encased in painted aluminium unless you're willing to pay for spectrum king or something nuts. Auto cobs are the bomb but you can build them yourself and save having them shipped from America. I hate to shun a customer for bigsm0 but ill help a local if I can.
Check out my thread in the indoor grow journal section called 'My favourite square meter' I'm running a light made of two Vero cutter kits and have citizen (those used in autocobs) ready to be added in.
Hope some of this helps mate, of you have any questions feel free to hit me up in happy to help