There are many good DIY LED threads on RC. Spend some time doing research before you start buying components. Several good threads devoted to the Lumia chips 5.2's being better IMO. Recently several have begun doing DIY's using the Radion upgrade Pucks available on the Echotech website (good value but requires a decent amount of DIY skill)
The "evil cluster" is another popular configuration for larger tanks, as is including some T5 supplement.
You'll probably want optics around 60 degree for a tank that deep. The Blue end of the spectrum 410nm to 480nm is the growth spectrum so you want to be heavy there and only provide enough other colors of light to achieve pleasing viewing (T5 is an easy way to do that)
Read up for a while then start asking more specific questions as you get your ideas narrowed down. Otherwise you'll just get a ton of opinions and there are a ton of different ways to do LED lighting that will achieve good results, so it is really up to you to narrow it down.