Need some first tank advice

[Shellies215]

I have a few things I could use advice on, I have kept african cichlids for 11 years, but I am now setting up my first saltwater tank, I will be using a 40 gallon breeder (not drilled) with versa top lid, and coralife T5HO 36" twin tube light fixture. Here's where the questions start, you can answer one or as many as you can...the short term plan is for a small school of chromis, a goby/pistol shrimp pair, a CUC, and maybe some mushroom coral once everything has been running good for a few months. (1) do I buy an Eshopps R-100, or build my own out of a 20h I already have? (2)What would you recommend to use for powerheads/ wavemaker in this setup?(3)will a coralife 125 super skimmer work, or should I be looking at something else?(4) would a chalk bass and some type of blenny be compatible in this setup? (5) what would be some recommendations for the critters in the cuc ( and how many) to be compatible with the pistol shrimp?