The best advice I can give(doesn't mean it's right) is figure out what lights you want. What do you want to achieve(basic blue and white or full spectrum). Figure out how many then figure out how you want to control them cause that may dictate which drivers you choose. If you want full spectrum this was a good link that I based mine off of.
https://www.dropbox.com/sh/3lx2w3u4u01tgre/8w-zoMzooF it's a excel file which you enter your length x width in the file and it will give you a good baseline.
You also want to figure out where you want to mount drivers and power supplies. I probably spent $100 more than I had to because I would buy stuff as I went along and then I would find things that were cooler.
If you go the ldd driver route I highly recommend the coralux boards. In my previous picture that's the blue board the drivers are on. If my controller ever becomes disconnected the lights will turn off because of a resistor or something they put on the board. Without this board if the controller were disconnected the lights would default to 100% possibly frying every coral you may have.
As far as controlling I'm not sure about the reef keeper but the apex has the ability to dim diy leds with a 0-10 volt analog. There's a website called Steve's led and I believe there is a device to convert 5v pwm to 10v analog. I have an apex but I bought it after I got the typhon. The typhon is simple sunrise to sunset controller with four channels of dimming. I have 4 channels. Royal blue, white, true violet, and ocean coral white from led group buy.
If you don't like soldering there are quite a few solderless leds that you just mount to the heatsink and push in the wire.
Another thing I used that was a bit more expensive but I liked it was the makers led heatsink
View attachment 1029View attachment 1030although this probably won't work for your application but heatsink USA sells a t slot heatsink which is similar to the makers led and convenient if you change your mind.
Sorry if I was a bit long winded but it was the most fun project I worked on