Hi Carlos @Verbose!
If you feel like that PixLite 4 is the right product for your projects then you should go for it!
I had a quick look, and the other only significant difference I could find is that the LeDMX4 PRO has a DMX in function, which could be handy in some situations; like for example, if you are working on a small project, someone else lighting design, you could plug your device and read the DMX that the programmer is sending out, manipulate that in TD, and output whatever you need (MIDI, OSC, DMX, Serial etc etc…). This particular LED board allows you to receive only 1x DMX universe though (=512 channels), and on top of that receiving DMX might not be a priority for you.
In terms of extra hardware, you can plug ethernet directly from the laptop.
I prefer to use a wifi router “in between” (that is, the laptop is connected to the router over wifi, the LED pixel board is connected to the router via ethernet). I find this solution helpful when testing, or installing the artwork, you can move the laptop around with you and be near the section that needs troubleshooting or tweaks. The router is optional, is a good to have and an affordable device to buy second hand, or someone might have a router to give away.
I go wifi only when testing, prototyping, troubleshooting… for show time I run an ethernet cable.
While we are here, I feel like saying that in terms of additional hardware, for your testing you will need an adequate DC power supply for your project (it depends on the project but often I prefer several smaller DC power supplies than a large centralised one controlling everything), some basic low voltage electrical wiring knowledge and some sort of encasing.
Before installing the final work i recommend to comply with any electrical standard required in your country, and consider hiring an electrician to spec the adequate amount of DC power supplies, cable size, fuses, power distribution etc…
I hope this helps!