Many thanks to you both. I'll start some investigation about development tools and languages as soon as I receive and prepare my Amigas.
Amiblitz looks quite nice! I still have the source code to a simple template of a shoot'em up game I made in BlitzBasic2. It's laguage and API were very clean, easy to delve into, and almost object-oriented (wich I liked).
But I really need to have the thing running in AmigaOS4/MorphOS/AROS with very little effort of porting, because if this home automation project really gets off the ground (and I already have 3 interested customers), I'll need to use something that is viable (obviously OS3 is not...). There is NO WAY I'm going to drive this system (server or clients) on top of Windows (not without the customer signing a responsability term, anyway). My choices are Linux, MacOS X, AmigaOS/AROS/MorphOS. Obviously, the big reason to get Amiga-based systems on this project are very much emotional...
I'll open a new thread when I have more info and pics about the system.