IMO, Remoras, Bakpaks or turbofloaters, are good hang ons for you size system, tehy can be slightly costly, but may come in handy
What is your preference on lr?
I am assuming you mean cured vs. uncured,
if this is the case, I only buy cured, uncured will eventually cure, but if you have your system running, you definitely do NOT want to add uncured to your system
If you mean, Fiji or tonga or soon,
Fiji is the most popular, therefore easier to find and less costly, differrent types(areas) have different densities, therefor you may need less of one type than another
Another note on cured, by curing the rock, not only can it go in your tank sooner, but some places even take the time to remove unwanteds, ie. mantis shrimp or whatever, I only buy locally now, because they place I get mine dos this, and I can add it right to my tank without problems, it is a little mor costly than MO, but IMO worth it
If you MO, it is all pretty much the same, most fiji MO comes through waltsmith, so it is the same rock, the only thing I do not like about MO personally is you should cure it even if it claims to be cured, but you will have die off in shipping, and at the lfs, you can pick your pieces, often with MO, you will wind up with small pieces, I was able to puchase 26-27 lb pieces with shape I really liked and he even had larger and smaller both available, MO often you wind up with smaller than fist size pieces and it doesn't quite add up to 45 lbs(ours was @35lbs, to guess), after you clean it and throw out the wrapping and rubble in the box
but these are only my opinions