time to upgrade.

the time has come for me to start piecing together my next tank.  as of right now the plan is to go with a 120-125  and to work on a sps dominant tank.
I have a lot of questions concerning this and figured this is one of the best places to start to get answers.
First off im currently using a 55gal sumpless  setup and for the most part it has worked out pretty well for me so that being the case id like to try and keep things as simple as reasonably possible.
everything will have to fit inside the stand for this build,  and i would like to try and stay away from the octopus of plumbing i have seen.
that being said, what are the things that are must haves to keep this tank flourishing, I realise  i will need a good skimmer and some good water movement. I dont know much about the pumps and such.

 

problem with a 120 is the fact its 24 deep. i measured and it just comes out too far from the wall. id much rather have a 4ft tank but it cant really be deeper then 18 inchs.

 

im working on that rodney, unfortuneatly im going to have to do this in phases i wont be able to do it all at once.