Since your starting fresh, you should sit down and literally draw out your aquascape IMHO
. This will give you an idea of how you want the tank to look style-wise (Will there be fish? Most reef fish like lots of nooks and crannies to hide in..) Once you have that, you can determine whats best as far as large, small, med pieces etc. For ex you may not be able to see from mypics, but my galaxea coral sits on top of a cool little LR
bridge. Do you want the left and right sides to flange? 1 straight line of rock? Theres really no wrong or right about what size or shape (Just keep it off the glass ; ) ) Keep in mind you can buy a couple large chucks of LR
and take a hammer/chisle to them and 'customize' them however you want..Kind of an advanced skill, but too many folks go looking for the 'perfect' piece, when all they had to do was knock a chunk off of what they already had. As for coral, most I have seen come on a pretty small piece of rock or have thier own base (calcium discharged by the coral). In any case, you should consider this in building your aquascape and leave a little shelf here and there. If you know what you want already, then you should have a pretty good idea of what to leave open where. (some corals need to placed higher up for lighting some down low some in direct current, some in very little current, etc.) Worse comes to worse, once you place it, its not too overly uncomfortable to simply...re-arrange it ; ) remember, its your tank, git-r-done the way you like..