I just went through this last month, got a lot of parts.
- Energy bar is awesome, can control all outlets for cleaning and feeding. Extra bar worth it if you need more than 8 plugs, if not, base bar is good.
- lunar module and led lights were good for night viewing without disturbing the tank (i run them at 10%) i can still see and everything opens up and acts normal.
- Water sensor kit if you are forgetful, the double with the module.
- I run vortechs so I got that module also which is great
- dos pump and software are awesome also if you go that route, skip the containers. Head on the dos pump is 24' so you can run right out of the bottles they come in.
- couple sets of ph calibration fluid
- feeder is good also, that dose not require a module/ their food for it is good too.
I'd skip the salinity probe. very inaccurate and extremely frustrating. Orp probe not necessary either.
On the budget side I would pick lunar and water sensors and ph calibration solution. Lunar not needed if you don't look at the tank at night.
I run a ap700 for my main light, I just use the kessil app for it, no complaints. I do have my kessil a80 controlled by the apex, need the cable for that one.