finally getting around to check out the thread, but of course my work blocks the pictures.
The biggest thing I can recommend is make sure whatever you do, create enough room for moving things around and removing equipment. You don't want to be cursing yourself for not leaving enough room to remove a skimmer cup, or pump and it gets stuck.
Make sure you add unions to piping - makes it easier for repairs
LOTS of ventilation - humidity/salt= corrosion.
Always stick to the KISS method (keep it simple). The easier something is to do, the more likely you are going to do it.
I know I have mentioned the reef brite XHOs. I would forgo those and get something different (if price is a concern). There are comparable LED's that are a lot less money.
Oh- for the sand bed, I did an mixture of sand and epoxy to create a life like sand bed. The benefit is once you place the rocks in the bed (has to be done at the same time), there won't be any places for detritus to get trapped. You can always add more sand to create a bed for wrasses to bury into.