The Bubble Magus 5 might be small but it's way too big for a Evo 13.5. It won't fit in the AIO chamber and would take up about 1/4 of the display if you put it in there! In fact, you don't even need a skimmer on an Evo.
If money is an issue then he shouldn't be thinking about Kessils, AI Prime, powerheads etc. You can make a chamber basket out of egg crate. The stock LED is fine to start with (add a cheap Nicrew timer from
Amazon). I have a Sicce 0.5 return pump and VCA RFG and that is enough flow to start with.
You can get the tank equipment for less than $200 ready to go. The bigger cost (which I have just been through) is the 'extras', such as rock, salt, RODI, test kits, cleaning tools, food, filter media, medications/dips etc.
I would buy the 'extras' first before worrying about LEDs, powerheads and skimmers.