Hi! I just bought a 125 yesterday!! I am going w/ a FOWLR predator tank.
I am using about 100lbs base rock, and another 75lbs of LR..
An ASM Skimmer, can't remember what # it is, I haven't bought it yet, and a 2-sets of plain-old 36" strip lights.... You do not need high-dollar lighting for this type of set-up....The standard lights that come with a tank are suitable...coraline algae is a low light algae, and will grow without the high intensity lighting....
Are you planning on using a sump??
I am going to try and find a used 55g, or 50g Long, and add a huge refugium to my system. I plan on having a Lionfish, Dog-faced puffer, Magnificent foxface, and an eel....so the Chaeto algae I add to the fuge will help with a bunch of messy eaters, and their bio-load...
HTH!