I agree with jharrell go for the OmniPro II. That is our best controller. It has everything built in and will give you the most capability. I was a little hesitant to say that because I work for HAI and people automatically assume you are a company automaton. By the way jharrell the check is in the mail... ;-)
As far as any PC based solution, IMHO, I prefer a dedicated automation controller. I started with a PC based system. It was good but more than once due to PC problems I would come home to a dark and sweltering home. I know that may people use PC based systems and may take offense, but my Omni just sits in the wall and runs 7/24, 365 days per year. It just works. I have PCs that augment the basic function of my Omni, but the primary controller is my Omni.
My Omni uses a LOT less power than a PC, it's silent, doesn't need Windows updates every week, can't get a virus, can run for 24 hours on battery in the event of a power failure and will last for years after the typical PC has become obsolete.
The other thing is ease of setup. Let's say you have a Russound whole house audio system. Just run a cable from the Russound serial port to one of the 5 serial ports on the Omni. Go into setup and set the port to Russound. That's it. It selects the correct baud rate and protocol. If you hit the audio button on a touch screen it comes up with the Russound interface. No modules to buy, no drivers to load. The same for Nuvo, HAI Hi-Fi, Xantec, Speaker Craft, etc.
It is also very easy to configure lighting systems. We support several and all of the drivers are built in.
As far as the web interface, the Omni does not have a built in "web" interface. You have a couple of options, you can Web-Link 2 on a PC, or WL3 on your Windows Home Server, or HAI Home control on your Media Center. You can also use Snap-Link on a PC/laptop or Snap-Link mobile on your phone. Both of these solutions allow you to monitor and control your Omni without having to have a PC running in the house. They communicate directly with the Omni using it's built in Ethernet port. Again no additional modules or drivers needed. Or you can just call your Omni with your phone. It has a built in voice phone interface. It even works during a power failure. If you have a Pronto remote you can control it directly from the remote, and again no need for a PC. Unless you really want a "web" interface you don't need a separate PC running in the house.
In addition to the HAI offerings mentioned above there are third party solutions for your iPhone. All of out software is PC based, but if you are a MAC user most of our apps can run on a MAC using Parallels or VMWare or other PC emulators/virtual machines.
Bottom line you will have a lot of capability and a lot of options.
Sorry I guess I got carried away, but I like what I do and I believe in our products.