I have done high tech planted fw tanks for the last 2 years and I have been interested in trying a sw planted tank. I was thinking of a 40 gallon breeder.

Livestock
No idea in this area but I was thinking eventually seahorses may be cool. Probably will keep this pretty light on the livestock though

Macros/corals/ect
I think I will just stick with macroalgaes for now may or may not add a couple corals in the future

Lighting
I have a 2x92w 36" PC with 10k bulbs. Do I need any actinic?

Substrate and liverock
How deep should my sand bed be? Do i need to add anything to it (I read stuff that Tom was saying about adding soil to it)? How much liverock should I have in the tank? Is there a big difference between all the different kinds of live rock that are out there?

Filter/water circulation
I assume I don't need a real filter since I have the liverock but know I need a good turnover rate. How much turnover do I need and whats the best way to get it (powerheads?)

Dosing
Does adding CO2 do anything in a macro tank? Any suggestions on a dosing schedule? I use dry ferts for my fw tanks so I have them all available.

I appreciate the help and I will make sure to post some photos when I get it up and running.