HomeAutomation WebServer

Hello all.

I am new in this forum, and I joined because I concluded that I probably want to start using Arduino.

What is my plan:

I want to build my own Home-Automation system.
It will consist or mostly Nexa buttons and Nexa Receivers (same as home-easy protocol I understand (433MHz)),
but I maybe also want to add some EnOcean temperature sensors.

Now I want to log and control everything with a some local control unit (Arduino).

Most of the controlling will be done with Nexa wireless switches. (As in, lights on/off. Temperature set-point to Occupied or Unoccupied levels).

But I also want to be able to fine-control the system and monitor.
The simplest way to me seems to be some web-page that I can access with PC or smart-phone, to adjust the set-points or see the temperature logs.

So the Arduino needs to have :
-Ethernet(/Wifi) access with WebServer.
-433MHz receiver
-433MHz transmitter (or combination)
-RS232 (/TTL) port to communicate with EnOcean interface.

So now my question:

What Arduino board is my best option for running a small web-server, and some background Automation code, that does have capability to work with multiple(2+) serial ports, which is cheap, and simple to learn as a beginner?
I prefer to have an Arduino with embedded Ethernet/Wifi port.

I do have programming experience in Basic, Assemble (8051), Basic-C, Pascal, ....
I am an Electronics Engineer, but currently without the easy option of producing my own PCB's, but with very good soldering skills.

PS. I do live in Europe.

What Arduino board is my best option for running a small web-server, and some background Automation code

None of the Arduinos has more than one core and none running an operating system. So, none of them have a "background" to run things in.

A Mega has enough memory for a decent web page, without having to store the file on an SD card. It will most likely handle all the things you need to do, as long as you do not write blocking code.