1- keeping trigger(s) ehh? have to very choosy in which ya try to mix (hell, that applies to most salwater fish!) as most all triggers are pugnacious.....
2- any particular reason for the live rock??? if to help with filtration, will need more than two chunks to affect filtration in a positive manner... if just for show, there are some really nice artificial corals being sold for tanks that would look better...
3- unless ya have some interesting critters hitchin a ride with the chunks, lighting would just be a matter of what works to illuminate yer fishies...