Okay, I'm not going to pretend I know what u are talking about 100% but I did some research on x10 controllers and Powerline Carriers and I think I have the general concept... that Programable relay that u linked to, can it handle 1000watt light? It says it's only rated for 500watts or do you just need an x10module that will handle it?
I woldnt run big draws through the programmable relay. I'd just have it fire a bigger relay (ice cube) for the light. (
Electro-Mechanical Cube Relays ) Pumps fans, etc its fine with.
The x10 stuff isn't too bad. It another option. I just use it for supliment. I have it turn on the web cams, so I check on the girls (and I think one dude (I hope!!) )from the road and to run the water pumps to water them (soil guy here) The PLC is programed for watering. I think I did 2 pumps per zone.
The x10 appliance modules can handle 15a. but a x10 set up is going to cost about $250, but it does hook into your computer for programing.
But I think as a single central controller the programmable relay is a good option. Will need to hang off the extra realy for the 1000watter, but nothing tragic.
The software is a free download and it has a simulator so you can test it out.