What hardware and op to use? im totaly lost

Hello

Today I use smartthings hub v2 with mqtt bridge to a rp3b with home assistant on. The problem is that smartthing hub v2 needs internet too much stuff and it will be a big delay when things are going to be done, and sometimes it doesn’t work at al.

I would need help choosing hardware that works well with home assistant and which one should use.
I would like to change from rp3b to avoid the uncertainty with flash memory

I have a nuc with an i3 8gig ram 64gig ssd, but what z-wave stick and which zigbee stick is best for this? should i run hasio directly on it or linux or windows. I would like to use blueiris for the cameras on the same device, is this possible? (blueiris require windows what i know) oh and is it a easy way to make the installation secure? does home assistant have a web service as samsung smartthing, where i connect the “hubb” to a account, so i doesnt need to worry about certificates and so on?

Then I am very worried that my device will not be supported.
I use the qubino z-wave range for all wall sockets and lamps, and I have many zigbee devices, MCT-visonic 340E magnetic connector for all windows and doors, xiaomi fire alarm, bosh motion sensor.
ID lock smart lock to the doors (z-wave)
Does alexa have good support in home assistant?

// Very grateful for all the help I can get
ps: excuse the bad grammar